Spring 2019 Study Union ReviewCHM 2040 / Chemistry 1

April 21st at 11:00AMMixture of multiple and free-response.

Disclaimer: This review is not meant to be an exhaustive review of what will be on the ACS exam. This is guide I (Sunmi Jin) have compiled myself using the course textbook, “A Molecular Approach” 4th edition by

Nivaldo Tro and CHM 2045 course material.

1. Classify each substance as a pure substance or mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as homogenous or heterogenous (multi-part question)

a. Sweat: ____________________b. Carbon dioxide: ____________________c. Aluminum: ____________________d. Vegetable soup: ____________________

2. A small airplane takes on 245 L of fuel. If the density of the fuel is 0.821 g/mL, what mass of fuel has the airplane taken on?

a. 201 • 103 gb. 201 gc. 201 kg d. 245,000 mL e. 201 • 103 mL

3. An acetaminophen suspension for infants contains 80mg/0.80mL suspension. The recommended dose is 15mg/kg body weight. How many mL of this suspension should be given to an infant weighting 14lb? (1 kg = 2.20462 lb) Assume two significant figures.

a. 9.5 mLb. 95.2 mLc. 0.95 mL d. 2.1 mLe. 21 mL

4. The first diagram depicts a compound in its liquid state. Which of the other diagrams best depicts the compound after it has evaporated into a gas?

5. Perform the calculation to the correct number of significant figures(43.998 • 0.00552) / 2.002 = ?

a. 0.121b. 0.12c. 0.12131d. 0.1213

6. Which property of rubbing alcohol is a chemical property? a. Density b. Flammabilityc. Boiling point d. Melting point

7. Three samples, each of a different substance, are weighed and their volume is measured. The results are tabulated. List the substances in order of decreasing density.

Mass VolumeSubstance I 10.0 g 10.0 mLSubstance II 10.0 kg 12.0 LSubstance III 12.0 mg 10.0 μL

a. III>II>Ib. I>II>IIIc. III>I>IId. II>I>III

8. What change is a physical change?a. Wood burning b. Iron rusting c. Dynamite exploding d. Gasoline evaporating

9. A hydrogen filled balloon is ignited and 1.50 g of hydrogen is reacted with 12.0 g of oxygen. What is the mass of water vapor that forms? (Water vapor is only product.)

a. 13.5 mol b. 13.5 gc. 1.35 mol d. 1.35 ge. 0.75 mol

10. Fill in the blanks to complete the table (fill in the blank) Symbol Ion Formed Number of

electrons in ionNumber of protons

in ionCa Ca2+ - -- Be2+ 2 -

Se - - 34In - - 49

11. Calculate the number of atoms in a sample 1.87 g Bi. a. 8.95 • 10-3

b. 5.39 • 1018

c. 8.95 • 10-6

d. 6.02 • 1023

e. 5.39 • 1021

12. Which statements about subatomic particles are false? a. If an atom has an equal number of protons and electrons, it will be charge-neutral. b. Electrons are attracted to protons. c. Electrons are much lighter than neutrons. d. Protons have twice the mass of neutrons.e. None of the above.

13. The mass ratio of sodium to fluorine in sodium fluoride is 1.21:1. A sample of sodium fluoride produces 28.8 g of sodium upon decomposition. How much fluorine (in grams) forms?

a. 23.8 gb. 28.3 gc. 2.38 gd. 2.83 ge. 238 g

14. Which statements are consistent with Dalton’s atomic theory as it was originally stated? a. Sulfur and oxygen atoms have the same mass.b. All cobalt atoms are identical. c. Potassium and chlorine atoms combine in a 1:1 ratio to form potassium chloride.d. Both B and C.e. None of the above.

15. Classify each element as an alkali metal, alkaline earth metal, halogen, or noble gas. a. sodium __________________b. iodine __________________c. calcium __________________d. barium __________________e. krypton __________________

16. Which pair of elements do you expect to be most similar? a. N and Ni b. Mo and Sn c. Cl and F d. Na and Mg e. Si and P

17. Write the balanced chemical equation for the reaction for aqueous sodium carbonate with aqueous copper (II) chloride to form solid copper (II) carbonate and aqueous sodium chloride.

a. Na2CO3 (aq) + CuCl2 (aq) CuCO3 (s) + 3 NaCl (aq)b. 2 Na2CO3 (aq) + CuCl2 (aq) CuCO3 (s) + 2 NaCl (aq)c. Na2CO3 (aq) + CuCl2 (aq) CuCO3 (s) + NaCl (aq)d. Na2CO3 (aq) + CuCl2 (aq) CuCO3 (s) + 2 NaCl (aq)e. 2 Na2CO3 (aq) + 3 CuCl2 (aq) 3 CuCO3 (s) + 2 NaCl (aq)

18. Calculate the empirical formula for caffeine based on its elemental mass percent composition. C: 49.48% , H: 5.19% , N: 28.85% , O: 16.48%

a. C4H5N2Ob. C10HN6O3

c. CH2NO2

d. C2H6N8O2

e. C7HN3O2

19. Give the acids their proper, respective names: H3PO4 and H2SO3.a. Acidic phosphate and sulfuric acid. b. Phosphoric acid and sulfurous acid. c. Phosphatidyl acetate and sulfuric acid.d. Phosphorous acid and sulfurous acid. e. Phosphoric acid and sulfuric acid.

20. Copper (II) fluoride contains 37.42% F by mass. Calculate the mass of fluorine in grams that is in 55.5 g of copper (II) fluoride.

a. 62.4 gb. 34.7 gc. 41.6 gd. 79.2 ge. 20.8 g

21. A sugar crystal contains approximately 1.8 * 1017 sucrose (C12H22O11) molecules. What is its mass in mg?

a. 12.9 mgb. 1.1 gc. 0.10 mgd. 10 ge. 0.92 mg

22. How many molecules of ethanol (C2H5OH) (the alcohol in alcoholic beverages) are present in 145 mL of ethanol? The density of ethanol is 0.789 g/cm3.

a. 1.50 * 1024 molecules C2H5OHb. 15.0 * 104 molecules C2H5OHc. 7.92 * 1016 molecules C2H5OHd. 15.0 * 1024 molecules C2H5OHe. 0.150 * 1014 molecules C2H5OH

23. Classify each hydrocarbon as an alkane, alkene, or alkyne. a. H2C=CH-CH3 ___________________________b. H3C-CH2-CH3 ___________________________c. HC≡C-CH3 ___________________________d. H3C-CH2-CH2-CH3 ___________________________

24. Fructose is a common sugar found in fruit. Elemental analysis of fructose gave the following mass percent composition: C 40.00% , H 6.72%,O 53.28%. The molar mass of fructose is 180.16 g/mol. Find the molecular formula of fructose. (Free response question!)

25. What is the name of the ionic compound that forms between calcium and oxygen?a. Calcium dioxide

b. Monocalcium monoxide c. Calcium (II) oxide d. Calcium oxidee. None of the above

26. Name each molecular compound. a. SO3 ___________________________b. SO2 ___________________________c. BrF5 ___________________________d. NO ___________________________

27. Urea (CH4N2O) is a common fertilizer that is synthesized b the reaction of ammonia (NH3) with carbon dioxide:

2 NH3 (aq) + CO2 (aq) CH4N2O (aq) + H2O (l)

In an industrial synthesis of urea, a chemist combines 136.4 kg of ammonia with 211.4 kg of carbon dioxide and obtains 168.4 kg of urea. Determine the limiting reagent, the theoretical yield of urea, and the percent yield for the reaction.

a. Limiting reagent: NH3 , theoretical yield: 480.8 kg , percent yield: 35.02%b. Limiting reagent: CO2 , theoretical yield: 70.04 kg , percent yield: 24.04%c. Limiting reagent: NH3 , theoretical yield: 240.4 kg , percent yield: 70.04% d. Limiting reagent: CO2 , theoretical yield: 288.5 kg , percent yield: 58.37%e. Limiting reagent: NH3 , theoretical yield: 70.04 kg , percent yield: 24.04%

28. Determine whether each compound is soluble or insoluble. a. AgNO3: ________________b. PbSO4: ________________c. KNO3: ________________d. (NH4)2S: ________________

29. Write the products and the balanced net ionic equations for the following reaction.

Na3PO4 (aq) + NiCl2 (aq) ____________________________

_______________________________________________________

30. Write the products and a balanced complete ion equation for the following reaction.

HC2H3O2 (aq) + K2CO3 (aq) ____________________________

__________________________________________________________

31. Determine whether the reaction is a redox reaction and identify the oxidizing agent (OA) and the reducing agent (RA).

Pb(NO3)2(aq) + Na2SO4(aq) PbSO4(s) + 2 NaNO3(aq)

a. Yes; OA= lead; RA= nitrateb. No; N/Ac. Yes; OA= sodium; RA= sulfate d. No; OA= oxygen; RA= nitrate e. Yes; OA= oxygen; RA= sulfate

32. If 123 mL of a 1.1 M glucose solution is diluted to 5.0 L, what is the molarity of the diluted solution?

a. 0.044 Mb. 27.06 Mc. 44.71 Md. 0.027 M e. .5590 M

33. A 25.0 mL sample of a 1.20 M potassium chloride solution is mixed with 15.0 mL of a 0.900 M lead (II) nitrate solution and this precipitation reaction occurs:

2 KCl (aq) + Pb(NO3)2 (aq) PbCl2 (s) + 2 KNO3 (aq)

The solid PbCl2 is collected, dried, and found to have a mass of 2.45 g. determine the limiting reactant, theoretical yield, and percent yield.

a. Lead nitrate, 3.75 g, 65.3%b. Potassium chloride, 3.75 g, 34.6%c. Pb(NO3)2, 4.72 g, 25.6%d. KCl, 90.33 g, 9.35%e. Pb(NO3)2, 76.29g, 12.3%

34. For each compound (all water-soluble), would you expect the resulting aqueous solution to conduct electrical current?

a. CsCl __________________b. CH3OH __________________

c. Ca(NO2)2 __________________d. C6H12O6__________________

35. Write balanced net ionic equation for the reaction between hydrobromic acid and potassium hydroxide.

__________________________________________________________

36. Iron (III) oxide reacts with carbon monoxide according to the equation:

Fe2O3 (s) + 3 CO (g) 2 Fe (s) + 3 CO2 (g)

A reaction mixture initially contains 22.55 g Fe2O3 and 14.78 g CO. Once the reaction has occurred as completely as possible, what mass (in g) of the excess reactant remains? (Free response)

37. A 25.00-mL sample of an unknown HClO4 solution requires titration with 22.62 mL of 0.2000 M NaOH to reach the equivalence point. What is the concentration of the unknown HClO4 solution? The neutralization reaction is:

HClO4 (aq) + NaOH (aq) H2O (l) + NaClO4 (aq)

a. 1.1 M HClO4

b. 0.235 M HClO4

c. 0.75 HClO4

d. 0.1810M HClO4

e. 1.89 M HClO4

38. The density of a 20.0% by mass ethylene glycol (C2H6O2) solution in water is 1.03 g/mL. Find the molarity of the solution. (Free response)

39. The air within a piston equipped with a cylinder absorbs 565 J of heat and expands from an initial volume of 0.10 L to a final volume of 0.85 L against an external pressure of 1.0 atm. What is the change in internal energy of the air within the piston?

a. 489.0 Jb. 564.25 J

c. 565.0 Jd. 490.0 Je. 641.0 J

40. The propane fuel (C3H8) used in gas barbeques burns according to the thermochemical equation

C3H8(g) + 5 O2(g) 3 CO2(g) + 4 H2O(g)∆H°rxn = - 2044kJ

If a pork roast must absorb 1.6 • 103 kJ to fully cook, and if only 10% of the heat produced by the barbeque is actually absorbed by the roast, what mass of CO2 is emitted into the atmosphere during the grilling of the pork roast?

a. 10.33 kgb. 1033 gc. 7.827 kg d. 78.27 ge. 10.33 g

41. A silver block, initially at 58.5 °C, is submerged into 100.0 g of water at 24.8 °C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 26.2 °C. What is the mass of the silver block? (specific heat of silver = 0.235 J/g•Cº, water = 4.18 J/g•Cº)

a. 39.48 gb. 41.03 g c. 77.09 gd. 29.23 ge. 34.22 g

42. Calculate ∆Hrxn for the reaction:

5 C(s) + 6 H2(g) C5H12(l)

Use the following reactions and given ∆H’s:

C5H12(l) + 8 O2(g) 5 CO2(g) + 6 H2O(g) ∆H = – 3244.8 kJC(s) + O2(g) CO2(g) ∆H = – 393.5 kJ2H2(g) + O2(g) 2H2O(g) ∆H = – 483.5 kJ

a. - 173.2 kJ b. 173.2 kJ c. - 4088.8 kJd. 367.8 kJe. - 49.01 kJ

43. Suppose that a person eats 2387 Calories per day. Convert this amount of energy into each unit. How many kilowatt-hours would this be?

a. 12.9 kWhb. 77.1 kWhc. 4.12 kWhd. 11.3 kWh e. 2.77 kWh

44. Which statement is true of the internal energy of a system and its surroundings during an energy exchange with a negative ∆Esys?

a. The internal energy of the system increases and the internal energy of the surroundings decreases.

b. The internal energy of both the system and the surroundings increases. c. The internal energy of both the system and the surroundings decreases. d. The internal energy of the system decreases and the internal energy of the

surroundings increases.e. None of the above

45. A system releases 622 kJ of heat and does 105 kJ of work on the surroundings. What is the change in internal energy of the system?

a. 7.27 • 102 kJb. –7.27 • 102 kJc. –2.93 • 1022 kJd. 2.93 • 1022 kJe. –9.92 • 102 kJ

46. Determine whether each process is exothermic or endothermic and indicate the sign of ∆H.

a. natural gas burning on a stove __________________b. isopropyl alcohol evaporating from skin __________________c. water condensing from steam __________________

47. When 0.514 g of biphenyl (C12H10) undergoes combustion in a bomb calorimeter, the temperature rises from 25.8 °C to 29.4 °C. Find ∆Erxn for the combustion of biphenyl in kJ/mol biphenyl. The heat capacity of the bomb calorimeter, determined in a separate experiment, is 5.86 kJ/°C.

a. –3.9• 103 kJ/molb. 6.3• 103 kJ/molc. –4.7 • 103 kJ/mold. 2.7 • 103 kJ/mole. –6.3• 103 kJ/mol

48. Zinc metal reacts with hydrochloric acid according to the balanced equation:

Zn (s) + 2 HCl (aq) ZnCl2 (aq) + H2 (g)

When 0.103 g of Zn (s) is combined with enough HCl to make 50.0 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 22.5 °C to 23.7 °C. Find ∆Hrxn for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g • °C as the specific heat capacity.)

a. –1.6 • 105 Jb. 4.32 • 105 Jc. –4.7 • 105 Jd. 1.6 • 105 Je. –3.7 • 105 J

49. During photosynthesis, plants use energy from sunlight to form glucose (C6H12O6) and oxygen from carbon dioxide and water. Write a balanced equation for photosynthesis and calculate ∆H°rxn using the values provided. .

Substance ∆Hfº (kJ/mol)CO2 (g) –393.5H2O (l) –285.8C6H12O6 (s) –1273.3O2 (g) 0

50. Hydrazine (N2H4) is a fuel used by some spacecraft. It is normally oxidized by N2O4 according to the equation:

N2H4 (l) + N2O4 (g) 2 N2O (g) + 2 H2O (g)

Calculate ∆H°rxn for this reaction using standard enthalpies of formation provided.

Substance ∆Hfº (kJ/mol)N2H4 (l) 50.6N2O4 (g) 9.16N2O (g) 81.6H2O (g) –241.8

a. –38.20 J/molb. 483.6 kJ/molc. –380.2 kJ/mold. 282.0 J/mole. –210.9 kJ/mol