51761889 Chemistry Questions

8/2/2019 51761889 Chemistry Questions

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1. What amount of oxygen, O 2, (in moles) contains 1.8 1022 molecules?

A. 0.0030

B. 0.030

C. 0.30

D. 3.0(1)

2. Which compound has the empirical formula with the greatest mass?

A. C 2H6

B. C 4H10

C. C 5H10

D. C 6H6(1)

3. __C 2H2(g) + __O 2(g) __ CO 2(g) + __ H 2O(g)

When the equation above is balanced, what is the coefficient for oxygen?

A. 2

B. 3

C. 4

D. 5(1)

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4. 3.0 dm 3 of sulfur dioxide is reacted with 2.0 dm 3 of oxygen according to the equation below.

2SO 2(g) +O 2(g) 2SO 3(g)

What volume of sulfur trioxide (in dm 3)is formed? (Assume the reaction goes to completion and

all gases are measured at the same temperature and pressure.)

A. 5.0

B. 4.0

C. 3.0

D. 2.0(1)

5. The relative molecular mass of aluminium chloride is 267 and its composition by mass is 20.3%Al and 79.7% chlorine. Determine the empirical and molecular formulas of aluminium chloride.

(Total 4 marks)

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6. Sodium reacts with water as follows.

2Na(s) + 2H 2O(l) 2NaOH(aq) + H 2(g)

1.15 g of sodium is allowed to react completely with water. The resulting solution is diluted to

250 cm3

. Calculate the concentration, in mol dm 3

, of the resulting sodium hydroxide solution.

(Total 3 marks)

7. (i) Calcium carbonate is added to separate solutions of hydrochloric acid and ethanoicacid of the same concentration. State one similarity and one difference in the observationsyou could make.

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(ii) Write an equation for the reaction between hydrochloric acid and calcium carbonate.

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(iii) Determine the volume of 1.50 mol dm 3 of hydrochloric acid that would react withexactly 1.25 g of calcium carbonate.

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(iv) Calculate the volume of carbon dioxide, measured at 273 K and1.01 10 5 Pa, which would be produced when 1.25 g of calcium carbonate reactscompletely with the hydrochloric acid.

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(Total 9 marks)

8. What volume (in dm 3) of 0.30 mol dm 3 NaCl solution can be prepared from 0.060 mol of solute?

A. 0.018

B. 0.20

C. 0.50

D. 5.0(1)

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9. What amount (in moles) is present in 2.0 g of sodium hydroxide, NaOH?

A. 0.050

B. 0.10

C. 20

D. 80(1)

10. A hydrocarbon contains 90 % by mass of carbon. What is its empirical formula?

A. CH 2

B. C 3H4

C. C 7H10

D. C 9H10(1)

11. Copper can react with nitric acid as follows.

3Cu +_HNO 3 _Cu(NO 3)2 +_H 2O + _NO

What is the coefficient for HNO 3 when the equation is balanced?

A. 4

B. 6

C. 8

D. 10(1)

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12. Lithium hydroxide reacts with carbon dioxide as follows.

2LiOH + CO 2 Li 2 CO 3 +H 2O

What mass (in grams) of lithium hydroxide is needed to react with 11 g of carbon dioxide?

A. 6

B. 12

C. 24

D. 48(1)

13. Which solution contains the smallest amount of H + ions?

A. 10.0 cm 3 of 0.250 mol dm 3 HCl

B. 20.0 cm 3 of 0.250 mol dm 3 HCl

D. 10.0 cm 3 of 0.500 mol dm 3 HCl

C. 10.0 cm3 of 0.250 mol dm 3 H2SO 4(1)

14. How many hydrogen atoms are contained in one mole of ethanol, C 2H5OH?

A. 5

B. 6

C. 1.0 10 23

D. 3.6 10 24

(1)

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15. The percentage by mass of the elements in a compound is

C = 72%, H = 12 %, O = 16%.

What is the mole ratio of C : H in the empirical formula of this compound?

A. 1 : 1

B. 1 : 2

C. 1 : 6

D. 6 : 1(1)

16. What is the coefficient for O 2 (g) when the equation below is balanced? 2

__C 3H8(g) + __O 2(g) __CO 2(g) + __H 2O(g)

A. 2

B. 3

C. 5

D. 7(1)

17. What amount of NaCl (in moles) is required to prepare 250 cm 3 of a 0.200 mol dm 3 solution?

A. 50.0

B. 1.25

C. 0.800

D. 0.0500(1)

18. 100 cm 3 of ethene, C 2H4, is burned in 400 cm3 of oxygen, producing carbon dioxide and some

liquid water. Some oxygen remains unreacted.

(a) Write the equation for the complete combustion of ethene.

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(b) Calculate the volume of carbon dioxide produced and the volume of oxygen remaining.

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(Total 4 marks)

19. (a) Write an equation for the formation of zinc iodide from zinc and iodine.

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(b) 100.0 g of zinc is allowed to react with 100.0 g of iodine producing zinc iodide.Calculate the amount (in moles) of zinc and iodine, and hence determine which reactantis in excess.

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(c) Calculate the mass of zinc iodide that will be produced.

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(Total 5 marks)

20. Which of the following contains the greatest number of molecules?

A. 1 g of CH 3Cl

B. 1 g of CH 2Cl2

C. 1 g of CHCl 3

D. 1 g of CCl 4

(1)

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21. Which of the following compounds has/have the empirical formula CH 2O?

I. CH 3COOH

II. C 6H12O6

III. C12

H22

O11

A. II only

B. III only

C. I and II only

D. II and III only(1)

22. Consider the equation below.

Fe(s) + S(s) FeS(s)

If 10.0 g of iron is heated with 10.0 g of sulfur to form iron(II) sulfide, what is the theoreticalyield of FeS in grams?

A. 10.0 + 10.0

B. 85.550.1091.87

C. 06.320.1091.87

D 06.320.1085.55

(1)

23. Assuming complete reaction, what volume of 0.200 mol dm 3 HCl(aq) is required to neutralize25 0 cm 3 of 0.200 mol dm 3 Ba(OH)

2(aq)?

A. 12.5 cm 3

B. 25.0 cm 3

C. 50.0 cm 3

D. 75.0 cm 3

(1)

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24. An oxide of copper was reduced in a stream of hydrogen as shown below.

h y d r o g e ng a s

H E A T

o x i d e o f c o pi n a d i s h

e x c e s s b u r n i n g

After heating, the stream of hydrogen gas was maintained until the apparatus had cooled.

The following results were obtained.

Mass of empty dish = 13.80 gMass of dish and contents before heating = 21.75 gMass of dish and contents after heating and leaving to cool = 20.15 g

(a) Explain why the stream of hydrogen gas was maintained until the apparatus cooled.

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(b) Calculate the empirical formula of the oxide of copper using the data above, assumingcomplete reduction of the oxide.

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(c) Write an equation for the reaction that occurred.

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(d) State two changes that would be observed inside the tube as it was heated.

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(Total 7 marks)

25. Consider the following equation.

2C4H10(g) + 130 2(g) 8CO 2(g) + 10H 2O(1)

How many moles of CO 2(g) are produced by the complete combustion of 58 g of butane,C4H10 (g)?

A. 4

B. 8

C. 12

D. 16(1)

26. 6.0 moles of Fe 2O3(s) reacts with 9.0 moles of carbon in a blast furnace according to theequation below.

Fe2O3(s) + 3C(s) 2Fe(s) + 3CO(g)

What is the limiting reagent and hence the theoretical yield of iron?

Limiting reagent Theoretical yield of ironA. Fe 2O3 6.0 molB. Fe

2O

3 12.0 molC. carbon 9.0 molD. carbon 6.0 mol

(1)

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27. What volume of 0.500 mol dm 3 HCl(aq) is required to react completely with 10.0 g of calciumcarbonate according to the equation below?

CaCO 3(s) + 2HCl(aq) CaCl 2(aq) + H 2O(l) + CO 2(g)

A. 100 cm3

B. 200 cm 3

C. 300 cm 3

D. 400 cm 3

(1)

28. 27.82 g of hydrated sodium carbonate crystals, Na 2CO 3. xH2O, was dissolved in water and made

up to 1.000 dm 3. 25.00 cm 3 of this solution was neutralized by 48.80 cm 3 of hydrochloric acidof concentration 0.1000 mol dm 3 .

(a) Write an equation for the reaction between sodium carbonate and hydrochloric acid.

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(b) Calculate the molar concentration of the sodium carbonate solution neutralized by thehydrochloric acid.

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(c) Determine the mass of sodium carbonate neutralized by the hydrochloric acid and hencethe mass of sodium carbonate present in the1.000dm 3 of solution.

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(d) Calculate the mass of water in the hydrated crystals and hence find the value of x.

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(Total 12 marks)

29. Which is a correct definition of the term empirical formula ?

A. formula showing the numbers of atoms present in a compound

B. formula showing the numbers of elements present in a compound

C. formula showing the actual numbers of atoms of each element in a compound

D. formula showing the simplest ratio of numbers of atoms of each element in a compound(1)

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30. The reaction of ethanal and oxygen can be represented by the unbalanced equation below.

__ CH 3CHO + __ O 2 __ CO 2 + __ H 2O

When the equation is balanced using the smallest possible integers, what is the coefficientfor O 2?

A. 3

B. 4

C. 5

D. 6(1)

31. The equation for the complete combustion of butane is

2C4H10 + 13O 2 8CO 2 + 10H 2O

What is the amount (in mol) of carbon dioxide formed by the complete combustion of threemoles of butane?

A. 4

B. 8

C. 12

D. 24(1)

32. Which solution contains the greatest amount (in mol) of solute?

A. 10.0 cm 3 of 0.500 mol dm 3 NaCl

B. 20.0 cm 3 of 0.400 mol dm 3 NaCl

C. 30.0 cm 3 of 0.300 mol dm 3 NaCl

D. 40.0 cm 3 of 0.200 mol dm 3 NaCl(1)

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33. The percentage composition by mass of a hydrocarbon is C = 85.6 % and H = 14.4 %.

(a) Calculate the empirical formula of the hydrocarbon.

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(b) A 1.00 g sample of the hydrocarbon at a temperature of 273 K and a pressure of 1.01 10 5 Pa(1.00 atm) has a volume of 0.399 dm 3.

(i) Calculate the molar mass of the hydrocarbon.

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(ii) Deduce the molecular formula of the hydrocarbon.

(1)(Total 5 marks)

34. How many oxygen atoms are present in 0.0500 mol carbon dioxide?

A. 3.01 10 22

B. 6.02 10 22

C. 6.02 10 23

D. 1.20 10 24

(1)

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35. Which pair of elements reacts most readily?

A. Li + Br 2

B. Li + Cl 2

C. K + Br 2

D. K + Cl 2(1)

36. Explain the following statements.

(a) The first ionization energy of sodium is

(i) less than that of magnesium.

(2)

(ii) greater than that of potassium.

(1)

(b) The electronegativity of chlorine is higher than that of sulfur.

.

.

.

.(2)

(Total 5 marks)

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37. Which of the following salts form coloured solutions when dissolved in water?

I. ScCL 3

II. FeCl 3

III. NiCl 2

IV. ZnCl 2

A. I and II only

B. II and III only

C. III and IV only

D. I, II, III and IV(1)

38. The compounds Na 2O, Al 2O3 and SO 2 respectively are

A. acidic, amphoteric and basic.

B. amphoteric, basic and acidic.

C. basic, acidic and amphoteric.

D. basic, amphoteric and acidic.(1)

39. The following table shows values that appear in the Data Booklet.

Table 1 Covalent (atomic) radii / 10 12 m

N 0 F70 66 58

Na Mg Al Si P S Cl186 160 143 117 110 104 99

Table 2 Ionic radii/10 12 m N3 O2 F

171 146 133 Na + Mg 2+ Al3+ Si4+ P3 S2 Cl

98 65 45 42 212 190 181

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Explain why

(i) the magnesium ion is much smaller than the magnesium atom.

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(ii) there is a large increase in ionic radius from silicon to phosphorus.

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(iii) the ionic radius of Na + is less than that of F .

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(Total 6 marks)

40. Which of the following properties of the halogens increase from F to I?

I. Atomic radius

II. Melting point

III. Electronegativity

A. I only

B. I and II only

C. I and III only

D. I, II and III(1)

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41. Which pair would react together most vigorously?

A. Li and Cl 2

B. Li and Br 2

C. K and Cl 2

D. K and Br 2(1)

42. Describe the acid-base character of the oxides of the period 3 elements Na to Ar. For sodiumoxide and sulfur trioxide, write balanced equations to illustrate their acid-base character.

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43. Table 6 of the Data Booklet lists melting points of the elements. Explain the trend in the melting points of the alkali metals, halogens and period 3 elements.

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44. (i) Explain how the first ionization energy of K compares with that of Na and Ar.

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(ii) Explain the difference between the first ionization energies of Na and Mg.

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(iii) Suggest why much more energy is needed to remove an electron from Na + than fromMg +.

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(Total 8 marks)

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45. Which properties of period 3 elements increase from sodium to argon?

I. Nuclear charge

II. Atomic radius

III. Electronegativity

A. I and II only

B. I and III only

C. II and III only

D. I, II and III(1)

46. Which general trends are correct for the oxides of the period 3 elements (Na 2O to Cl 2O)?

I. Acid character decreases.

II. Electrical conductivity (in the molten state) decreases.

III. Bonding changes from ionic to covalent.

A. I and II only

B. I and III only

C. II and III only

D. I, II and III(1)

47. Outline the reasoning for the following in terms of electronic configuration:

(i) The first ionization energy of Al is lower than that of Mg.

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(ii) V 3+(aq) is coloured and can behave as a reducing agent, whereas Zn 2+(aq) is not colouredand does not behave as a reducing agent.

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(Total 8 marks)

48. Define the term ligand . Cu 2+(aq) reacts with ammonia to form the complex ion[Cu(NH 3)4]

2+. Explain this reaction in terms of an acid-base theory, and outline the bonding in

the complex ion formed between Cu2+

and NH 3.

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49. For which element are the group number and the period number the same?

A. Li

B. Be

C. B

D. Mg(1)

50. Which of the physical properties below decrease with increasing atomic number for both thealkali metals and the halogens?

I. Atomic radius

II. Ionization energy

III. Melting point

A. I only

B. II only

C. III only

D. I and III only(1)

51. Which of the following oxides is (are) gas(es) at room temperature?

I. SiO 2

II. P 4O6

III. SO 2

A. I only

B. II only

C. I and II only


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52. Which of the reactions below occur as written?

I. Br 2 + 2I 2Br + I2

II. Br 2 + 2Cl 2Br + Cl 2

A. I only

B. II only

C. Both I and II

D. Neither I nor II(1)

53. Rubidium is an element in the same group of the periodic table as lithium and sodium.It is likely to be a metal which has a

A. high melting point and reacts slowly with water.

B. high melting point and reacts vigorously with water.

C. low melting point and reacts vigorously with water.

D. low melting point and reacts slowly with water.(1)

54. When the following species are arranged in order of increasing radius, what is the correct order?

A. Cl , Ar, K +

B. K +, Ar , Cl

C. Cl , K +, Ar

D. Ar, Cl , K +

(1)

55. Nitrogen is found in period 2 and group 5 of the periodic table.

(i) Distinguish between the terms period and group .

(1)

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(ii) State the electron arrangement of nitrogen and explain why it is found in period 2 andgroup 5 of the periodic table.

(3)

(Total 4 marks)

56. Table 8 of the Data Booklet gives the atomic and ionic radii of elements. State and explain thedifference between

(i) the atomic radius of nitrogen and oxygen.

(2)

(ii) the atomic radius of nitrogen and phosphorus.

(1)

(iii) the atomic and ionic radius of nitrogen.

(2)

(Total 5 marks)

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57. Elements with atomic number 21 to 30 are d-block elements.

(a) Identify which of these elements are not considered to be typical transition elements.

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(b) Complex ions consist of a central metal ion surrounded by ligands. Define the termligand .

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(c) Complete the table below to show the oxidation state of the transition element .(3)

ion Cr 2O72 [CuCl 4]

2 [Fe(H 2O)6]3+

oxidation state

(d) Identify two transition elements used as catalysts in industrial processes, stating the process in each case.

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(e) Apart from the formation of complex ions and apart from their use as catalysts, state twoother properties of transition elements.

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(Total 10 marks)

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58. What increases in equal steps of one from left to right in the periodic table for the elementslithium to neon?

A. the number of occupied electron energy levels

B. the number of neutrons in the most common isotope

C. the number of electrons in the atom

D. the atomic mass(1)

59. Which property decreases down group 7 in the periodic table?

A. atomic radius

B. electronegativity

C. ionic radius

D. melting point(1)

60. State and explain the trends in the atomic radius and the ionization energy

(i) for the alkali metals Li to Cs.

(4)

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(ii) for the period 3 elements Na to Cl.

(4)

(Total 8 marks)

61. (i) Describe three similarities and one difference in the reactions of lithium and potassium with water.

(4)

(ii) Give an equation for one of these reactions. Suggest a pH value for the resulting solution,and give a reason for your answer.

(3)

(Total 7 marks)

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62. (a) Classify each of the following oxides as acidic, basic or amphoteric.

(i) aluminium oxide

(1)

(ii) sodium oxide

(1)

(iii) sulfur dioxide

(1)

(b) Write an equation for each reaction between water and

(i) sodium oxide

(1)

(ii) sulfur dioxide.

(1)(Total 5 marks)

63. Which two elements react most vigorously with each other?

A. chlorine and lithium

B. chlorine and potassium

C. iodine and lithium

D. iodine and potassium(1)

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64. Which is an essential feature of a ligand?

A. a negative charge

B. an odd number of electrons

C. the presence of two or more atoms

D. the presence of a non-bonding pair of electrons(1)

65. For the elements of period 3 (Na to Ar), state and explain

(i) the general trend in ionization energy

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(ii) any exceptions to the general trend.

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(Total 6 marks)

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66. Explain the following features of the melting points of the period 3 elements. Refer to bondingand structure, and use information from Table 6 in the Data Booklet.

(i) The difference between the values for sodium and magnesium

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(ii) The high value for silicon

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(iii) The difference between the values for chlorine and argon

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(Total 7 marks)

67. By reference to the structure and bonding in the compounds NaCl and SiCl 4

(i) state and explain the differences in conductivity in the liquid state.

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(ii) predict an approximate pH value for a solution formed by adding each compoundseparately to water.

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(Total 7 marks)

68. Two characteristics of the d-block (transition) elements are that they exhibit variable oxidationstates and form coloured compounds.

(i) State two possible oxidation states for iron and explain these in terms of electronarrangements.

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(ii) Explain why many compounds of d-block (transition) elements are coloured.

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(Total 5 marks)

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69. Consider the composition of the species W, X, Y and Z below. Which species is an anion?

Species Number of protons Number of neutrons Number of electrons

W 9 10 10

X 11 12 11

Y 12 12 12

Z 13 14 10

A. W

B. X

C. Y

D. Z(1)

70. Energy levels for an electron in a hydrogen atom are

A. evenly spaced.

B. farther apart near the nucleus.

C. closer together near the nucleus.

D. arranged randomly.(1)

71. Which is related to the number of electrons in the outer main energy level of the elements fromthe alkali metals to the halogens?

I. Group number

II. Period number

A. I only

B. II only

C. Both I and II

D. Neither I nor II(1)

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72. How do bond length and bond strength change as the number of bonds between two atomsincreases?

Bond length Bond strength

A. increases increases

B. increases decreases

C. decreases increases

D. decreases decreases(1)

73. Which of the following is true for CO 2?

C==O bond CO 2 molecule

A. polar non-polar B. non-polar polar

C. polar polar

D. non-polar non-polar (1)

74. The molar masses of C 2H6, CH 3OH and CH 3F are very similar. How do their boiling pointscompare?

A. C 2H6 < CH 3OH < CH 3F

B. CH 3F < CH 3OH < C 2H6

C. CH 3OH < CH 3F < C 2H6

D. C 2H6 < CH 3F < CH 3OH(1)

75. The element vanadium has two isotopes,V50

23 andV5123 , and a relative atomic mass of 50.94.

(a) Define the term isotope .

.

.(1)

(b) State the number of protons, electrons and neutrons inV50

23 .

.

.

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(2)

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(c) State and explain which is the more abundant isotope.

.

.(1)

(d) State the name and the mass number of the isotope relative to which all atomic masses aremeasured.

.(1)

(Total 5 marks)

76. What is the electron configuration for an atom with Z = 22?

A. 1s22s

22p

63s

23p

63d

4

B. 1s 22s22p63s23p64s24p2

C. 1s 22s22p63s23p63d24p2

D. 1s 22s22p63s23p64s23d2

(1)

77. (a) The diagram below (not to scale) represents some of the electron energy levels inthe hydrogen atom.

________________________________ n = ________________________________ n = 6 ________________________________ n = 5

________________________________ n = 4

________________________________ n = 3

________________________________ n = 2

________________________________ n = l

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(i) Draw an arrow on the diagram to represent the electron transition for the ionizationof hydrogen. Label this arrow A.

(2)

(ii) Draw an arrow on the diagram to represent the lowest energy transition in thevisible emission spectrum. Label this arrow B.

(2)(Total 4 marks)

78. Tritium,T3

1 , is an isotope of hydrogen.

(i) State the number and type of sub-atomic particles in a tritium atom and the location of each type.

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(ii) Write balanced equations to represent the formation of the following compounds, startingwith T 2 or T 2O.

NT 3: ...............................................................................................................

............................................................................................................................

NaOT: .............................................................................................................

............................................................................................................................(4)

(Total 6 marks)

79. What is the correct number of each particle in a fluoride ion, 19F ?

protons neutrons electrons

A. 9 10 8

B. 9 10 9

C. 9 10 10

D. 9 19 10(1)

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80. Which statement is correct for the emission spectrum of the hydrogen atom?

A. The lines converge at lower energies.

B. The lines are produced when electrons move from lower to higher energy levels.

C. The lines in the visible region involve electron transitions into the energy level closest tothe nucleus.

D. The line corresponding to the greatest emission of energy is in the ultraviolet region.(1)

81. Which is the correct description of polarity in F 2 and HF molecules?

A. Both molecules contain a polar bond.

B. Neither molecule contains a polar bond.

C. Both molecules are polar.

D. Only one of the molecules is polar.(1)

82. Which types of bonding are present in CH 3CHO in the liquid state?

I. Single covalent bonding

II. Double covalent bonding

III. Hydrogen bonding

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

(1)

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83. Which statement(s) is/are generally true about the melting points of substances?

I. Melting points are higher for compounds containing ions than for compoundscontaining molecules.

II. A compound with a low melting point is less volatile than a compound with a highmelting point.

III. The melting point of a compound is decreased by the presence of impurities.

A. I only

B. I and III only

C. II and III only

D. I, II and III(1)

84. (a) State a physical property that is different for isotopes of an element.

.....................................................................................................................................(1)

(b) Chlorine exists as two isotopes, 35Cl and 37Cl. The relative atomic mass of chlorineis35.45. Calculate the percentage abundance of each isotope.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(2)

(Total 3 marks)

85. What is the correct sequence for the processes occurring in a mass spectrometer?

A. vaporization, ionization, acceleration, deflection

B. vaporization, acceleration, ionization, deflection

C. ionization, vaporization, acceleration, deflection

D. ionization, vaporization, deflection, acceleration(1)

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86. Electrons are directed into an electric field from left to right as indicated by the arrow in thediagram below. Which path is most probable for these electrons?

1

2

34

+

A. 1

B. 2

C. 3

D. 4(1)

87. How many valence electrons are present in an atom of an element with atomic number 16?

A. 2

B. 4

C. 6

D. 8(1)

88. (a) Define the term isotope .

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(2)

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(b) A sample of argon exists as a mixture of three isotopes.

mass number 36, relative abundance 0.337 %mass number 38, relative abundance 0.0630 %mass number 40, relative abundance 99.6 %

Calculate the relative atomic mass of argon.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(2)

(c) State the number of electrons, protons and neutrons in the ion 56Fe3+.

electrons: ............................. protons: ............................. neutrons: ...........................(2)

(Total 6 marks)

89. How many protons, neutrons and electrons are there in the species 26Mg 2+ ?

Protons Neutrons Electrons

A. 10 14 12

B. 12 14 10

C. 12 26 10

D. 14 12 12(1)

90. What is the total number of p orbitals containing one or more electrons in germanium (atomicnumber 32)?

A. 2

B. 3

C. 5

D. 8(1)

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91. (a) Define the term isotope .

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(2)

(b) A sample of gallium exists as two isotopes, 69Ga, relative abundance 61.2 %, and 71Ga,relative abundance 38.8 %. Calculate the relative atomic mass of gallium.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(1)

(Total 3 marks)

92. (a) Evidence for the existence of energy levels in atoms is provided by line spectra.State how a line spectrum differs from a continuous spectrum.

.....................................................................................................................................

.....................................................................................................................................(1)

(b) On the diagram below draw four lines in the visible line spectrum of hydrogen.(1)

L o w e n e r g y H i g h

(c) Explain how the formation of lines indicates the presence of energy levels.

.....................................................................................................................................

.....................................................................................................................................(1)

(Total 3 marks)

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93. (i) State the full electron configuration for argon.

(1)

(ii) Give the formulas of two oppositely charged ions which have the same electron

configuration as argon.

(2)

(Total 3 marks)

94. A certain sample of element Z contains 60% of 69 Z and 40% of 71 Z . What is the relative atomicmass of element Z in this sample?

A. 69.2

B. 69.8

C. 70.0

D. 70.2(1)

95. What is the difference between two neutral atoms represented by the symbols 2759

Co and 2859

Ni ?

A. The number of neutrons only.

B. The number of protons and electrons only.

C. The number of protons and neutrons only.

D. The number of protons, neutrons and electrons.(1)

96. A certain sample of element Z contains 60% of 69 Z and 40% of 71 Z . What is the relative atomicmass of element Z in this sample?

A. 69.2

B. 69.8

C. 70.0

D. 70.2(1)

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97. Which ion would undergo the greatest deflection in a mass spectrometer?

A. 16O+

B. 16O2+

C. 18O2+

D. ( 16O18O)+

(1)

98. How many electrons are there in one 1224

Mg 2+ ion?

A. 10

B. 12

C. 14

D. 22(1)

99. The electron arrangement of sodium is 2.8.1. How many occupied main electron energy levelsare there in an atom of sodium?

A. 1

B. 3

C. 10

D. 11(1)

100. State the number of protons, electrons and neutrons in the ion 715

N3 .

(Total 2 marks)

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101. How many electrons are there in all the d orbitals in an atom of xenon?

A. 10

B. 18

C. 20

D. 36(1)

102. What is the formula for the compound formed by calcium and nitrogen?

A. CaN

B. Ca 2 N

C. Ca 2 N3

D. Ca 3 N2(1)

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103. The boiling points of the hydrides of the group 6 elements are shown below.

4 0 0

3 0 0

2 0 0

1 0 0

0

B o i l i n g p o i n t / K

H O H S H S e H T2 2 2 2

(i) Explain the trend in boiling points from to H 2S to H 2Te.

.

.

.

.(2)

(ii) Explain why the boiling point of water is higher than would be expected from the grouptrend.

.

.

.

.(2)

(Total 4 marks)

104. (i) State the shape of the electron distribution around the oxygen atom in the water molecule and state the shape of the molecule.

.

.(2)

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(ii) State and explain the value of the HOH bond angle.

..

..

..

..(2)

(Total 4 marks)

105. Explain why the bonds in silicon tetrachloride, SiCl 4, are polar, but the molecule is not.

(Total 2 marks)

106. The diagrams below represent the structures of iodine, sodium and sodium iodide.

A B C

(a) (i) Identify which of the structures ( A , B and C ) correspond to iodine,sodium and sodium iodide.

.

.

.(1)

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(ii) State the type of bonding in each structure.

.

.

.(3)

(b) (i) Sodium and sodium iodide can both conduct electricity when molten, but only sodium can conduct electricity when solid. Explain this difference inconductivity in terms of the structures of sodium and sodium iodide.

.

.

.

.

.

.(4)

(ii) Explain the high volatility of iodine compared to sodium and sodium iodide.

.

.

.

.(2)

(Total 10 marks)

107. What is the best description of the carbon-oxygen bond lengths in 2

3CO

?

A. One short and two long bonds

B. One long and two short bonds

C. Three bonds of the same length

D. Three bonds of different lengths(1)

108. What is the number of sigma ( ) and pi ( ) bonds and the hybridization of the carbon atom in

O

C HH O

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- Sigma Pi Hybridization

A. 4 1 sp2

B. 4 1 sp3

C.3

2sp

3

D. 3 1 sp2

(1)

109. Element X is in group 2, and element Y in group 7, of the periodic table. Which ions will be present in the compound formed when X and Y react together?

A. X + and Y

B. X 2+

and Y

C. X + and Y 2

D. X 2 and Y +

(1)

110. (a) Draw the Lewis structure of methanoic acid, HCOOH.

(1)

(b) In methanoic acid, predict the bond angle around the(2)

(i) carbon atom. .....................................................................................................

(ii) oxygen atom bonded to the hydrogen atom. ...................................................

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(c) State and explain the relationship between the length and strength of the bonds betweenthe carbon atom and the two oxygen atoms in methanoic acid.

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................

......................................................................................................................................(3)

(Total 6 marks)

111. Which of the following increase(s) for the bonding between carbon atoms in the sequence of molecules C 2H6, C 2H4 and C 2H2?

I. Number of bonds

II. Length of bonds

III. Strength of bonding

A. I only

B. I and III only

C. III only

D. I, II and III(1)

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112. Which of the following contain a bond angle of 90 ?

I. PC1 4+

II. PCl 5

III. PCl 6

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

(1)

113. Which allotropes contain carbon atoms with sp 2 hybridization?

I. Diamond

II. Graphite

III. C 60 fullerene

A. I and II only

B. I and III only

C. II and III only

D. I, II and III(1)

114. State the complete electronic configuration of bromine, Br and the iron(III) ion, Fe 3+.

Br: .

Fe3+: .(Total 2 marks)

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115. The boiling points of the hydrides of group 6 elements increase in the order

H2S < H 2Se < H 2Te < H 2O.

Explain the trend in the boiling points in terms of bonding.

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................(Total 3 marks)

116. Identify which of the compounds butane, chloroethane, propanone and propan-1-ol are

(i) insoluble in water and give your reasoning.

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................(2)

(ii) water soluble and give your reasoning.

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................ (2)(Total 4 marks)

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117. (i) Draw the Lewis structures for carbon monoxide, carbon dioxide and the carbonateion.

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................(3)

(ii) Identify the species with the longest carbon-oxygen bond and explain your answer.

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................(3)

(Total 6 marks)

118. Hydrazoic acid, N 3H, can be represented by two possible Lewis structures in which the atomscan be arranged as NNNH.

(i) Draw the two possible Lewis structures of N 3H.

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

(2)

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(ii) Predict the NNN and HNN bond angles in each case and give your reasoning.

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................

................................................................................................................................................(6)

(iii) Predict the hybridization of the N atom bonded to the hydrogen atom in each case.

................................................................................................................................................

................................................................................................................................................(2)

(Total 10 marks)

119. What is the formula of an ionic compound formed by element X (group 2) and element Y

(group 6)?

A. X 3Y

B. X 2Y

C. XY 2

D. XY (1)

120. Based on electronegativity values, which bond is the most polar?

A. BC

B. CO

C. NO

D. OF(1)

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121. What is the Lewis (electron dot) structure for sulfur dioxide?

A. O S

B. O S

C. O

D. O

(1)

122. Which substance is most soluble in water (in mol dm 3) at 298 K?

A. CH 3CH 3

B. CH 3OCH 3

C. CH 3CH 2OH

D. CH 3CH 2CH 2CH 2OH(1)

123. (i) Draw Lewis (electron dot) structures for CO 2 and H 2S showing all valence

electrons.(2)

(ii) State the shape of each molecule and explain your answer in terms of VSEPR theory.

CO 2 .............................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

H2S .............................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(4)

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(iii) State and explain whether each molecule is polar or non-polar.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(2)

(Total 8 marks)

124. Identify the strongest type of intermolecular force in each of the following compounds.

CH 3Cl ...................................................................................................................................

CH 4 .......................................................................................................................................

CH 3OH .................................................................................................................................(Total 3 marks)

125. Which of the following species is (are) planar (has (have) all the atoms in one plane)?

I. 3 2CO

II. 3 NO

III. 3 2SO

A. I only

B. II only

C. I and II only


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126. What is the molecular shape and the hybridization of the nitrogen atom in NH 3?

Molecular shape Hybridization

A. tetrahedral sp3

B. trigonal planar sp2

C. trigonal pyramidal sp2

D. trigonal pyramidal sp3

(1)

127. Which statement about sigma and pi bonds is correct?

A. Sigma bonds are formed only by s orbitals and pi bonds are formed only by p orbitals.

B. Sigma bonds are formed only by p orbitals and pi bonds are formed only by s orbitals.

C. Sigma bonds are formed by either s or p orbitals, pi bonds are formed only by p orbitals.

D. Sigma and pi bonds are formed by either s or p orbitals.(1)

128. Draw Lewis (electron dot) structures for the following ions.

NO 2

NO 2+

Determine and explain the shape of each ion.

(Total 6 marks)

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129. (i) List the following substances in order of increasing boiling point (lowest first).

CH 3CHO C 2H6 CH 3COOH C 2H5OH

(2)

(ii) State whether each compound is polar or non-polar, and explain the order of boiling points in (c)(i).

(8)

(Total 10 marks)

130. According to VSEPR theory, repulsion between electron pairs in a valence shell decreases inthe order

A. lone pair-lone pair > lone pair-bond pair > bond pair-bond pair.

B. bond pair-bond pair > lone pair-bond pair > lone pair-lone pair.

C. lone pair-lone pair > bond pair-bond pair > bond pair-lone pair.

D. bond pair-bond pair > lone pair-lone pair > lone pair-bond pair.(1)

131. Which molecule is linear?

A. SO 2

B. CO 2

C. H 2S

D. Cl 2O(1)

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132. Why is the boiling point of PH 3 lower than that of NH 3?

A. PH 3 is non-polar whereas NH 3 is polar.

B. PH 3 is not hydrogen bonded whereas NH 3 is hydrogen bonded.

C. Van der Waals forces are weaker in PH 3 than in NH 3

D. The molar mass of PH 3 is greater than that of NH 3(1)

133. Which molecule is non-polar?

A. H 2CO

B. SO 3

C. NF 3

D. CHCl 3(1)

134. (a) An important compound of nitrogen is ammonia, NH 3. The chemistry of ammoniais influenced by its polarity and its ability to form hydrogen bonds. Polarity can beexplained in terms of electronegativity.

(i) Explain the term electronegativity .

(2)

(ii) Draw a diagram to show hydrogen bonding between two molecules of NH 3.The diagram should include any dipoles and/or lone pairs of electrons

(3)

(iii) State the HNH bond angle in an ammonia molecule.

(1)

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(iv) Explain why the ammonia molecule is polar.

(1)

(b) Ammonia reacts with hydrogen ions forming ammonium ions, NH 4+.

(i) State the HNH bond angle in an ammonium ion.

(1)

(ii) Explain why the HNH bond angle of NH 3 is different from the HNH bond

angle of NH 4+

; referring to both species in your answer.

(3)

(Total 11 marks)

135. NO 3

is trigonal planar and NH 3 is trigonal pyramidal. What is the type of hybridization of N ineach of these species?

N in NO3

N in NH 3

A. sp2 sp3

B. sp2 sp2

C. Sp3 sp2

D. sp3 sp3

(1)

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136. Consider the following statements.

I. All carbon-oxygen bond lengths are equal in CO 3 2

.

II. All carbon-oxygen bond lengths are equal in CH 3COOH.

III. All carbon-oxygen bond lengths are equal in CH 3COO.

Which statements are correct?

A. I and II only

B. I and III only

C. II and III only

D. I, II and III (1)

137. In 1954 Linus Pauling was awarded the Chemistry Nobel Prize for his work on the nature of thechemical bond. Covalent bonds are one example of intramolecular bonding.

Explain the formation of the following.

(i) bonding

(2)

(ii) bonding

(2)

(iii) double bonds

(1)

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(iv) triple bonds

(1)

(Total 6 marks)

138. Atomic orbitals can mix by hybridization to form new orbitals for bonding.

Identify the type of hybridization present in each of the three following molecules.Deduce and explain their shapes.

(i) OF 2

(3)

(ii) H 2CO

(3)

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(iii) C 2H2

(3)

(Total 9 marks)

139. Three scientists shared the Chemistry Nobel Prize in 1996 for the discovery of fullerenes.Fullerenes, like diamond and graphite, are allotropes of the element carbon.

(i) State the structures of and the bonding in diamond and graphite.

(2)

(ii) Compare and explain the hardness and electrical conductivity of diamond and graphite.

(4)

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(iii) Predict and explain how the hardness and electrical conductivity of C 60 fullerene wouldcompare with that of diamond and graphite.

(4)

(Total 10 marks)

140. What happens when sodium and oxygen combine together?

A. Each sodium atom gains one electron.

B. Each sodium atom loses one electron.

C. Each oxygen atom gains one electron.

D. Each oxygen atom loses one electron.(1)

141. Which statement is correct about two elements whose atoms form a covalent bond witheach other?

A. The elements are metals.

B. The elements are non-metals.

C. The elements have very low electronegativity values.

D. The elements have very different electronegativity values.

(1)

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142. In ethanol, C 2H5OH (l), there are covalent bonds, hydrogen bonds and van der Waals forces.Which bonds or forces are broken when ethanol is vaporized?

A. only hydrogen bonds

B. covalent bonds and hydrogen bonds

C. covalent bonds and van der Waals forces

D. hydrogen bonds and van der Waals forces(1)

143. Which substance has the lowest electrical conductivity?

A. Cu(s)

B. Hg(l)

C. H 2(g)

D. LiOH(aq)(1)

144. The letters W , X, Y and Z represent four consecutive elements in the periodic table.The number of electrons in the highest occupied energy levels are:

W : 3, X: 4, Y: 5, Z : 6

Write the formula for

(i) an ionic compound formed from W and Y , showing the charges.

(2)

(ii) a covalent compound containing X and Z .

(1)

(Total 3 marks)

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145. State the type of bonding in the compound SiCl 4. Draw the Lewis structure for this compound.

(Total 3 marks)

146. Outline the principles of the valence shell electron pair repulsion (VSEPR) theory.

(Total 3 marks)

147. (i) Use the VSEPR theory to predict and explain the shape and the bond angle of eachof the molecules SCl 2 and C 2Cl2

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(6)

(ii) Deduce whether or not each molecule is polar, giving a reason for your answer.

(3)

(Total 9 marks)

148. Which statement best describes the attraction present in metallic bonding?

A. the attraction between nuclei and electrons

B. the attraction between positive ions and electrons

C. the attraction between positive ions and negative ions

D. the attraction between protons and electrons(1)

149. Which statement is correct about multiple bonding between carbon atoms?

A. Double bonds are formed by two bonds.

B. Double bonds are weaker than single bonds.

C. bonds are formed by overlap between s orbitals.

D. bonds are weaker than sigma bonds.(1)

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150. Which statements are correct about diamond, graphite and a C 60 fullerene?

I. The poorest electrical conductor of the three is diamond.

II. The atoms in graphite and C 60 fullerene are sp2 hybridized.

III. The atoms in diamond and C 60 fullerene are arranged in hexagons.

A. I and II only

B. I and III only

C. II and III only

D. I, II and III(1)

151. For the following compounds

PCl 3 , PCl 5 , POCl 3

(i) Draw a Lewis structure for each molecule in the gas phase.(Show all non-bonding electron pairs.)

.....................................................................................................................................

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(ii) State the shape of each molecule and predict the bond angles.

.....................................................................................................................................

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.....................................................................................................................................

.....................................................................................................................................(6)

(iii) Deduce whether or not each molecule is polar, giving a reason for your answer.

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(3)

(Total 12 marks)

152. (i) Explain the meaning of the term hybridization .

.....................................................................................................................................

.....................................................................................................................................

.....................................................................................................................................(1)

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(ii) Discuss the bonding in the molecule CH 3CHCH 2 with reference to

the formation of and bonds the length and strength of the carbon-carbon bonds the types of hybridization shown by the carbon atoms

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51761889 Chemistry Questions

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