7/29/2019 2013 ME Magway, Chemistry

1/4

2013MATRICI]LATION EXAMINATIONDEPARTMENT OF MYANMAR EXAMINATIONCIIEMISTRY Time Allowed: 3lloursWRITE YOUR ANSWERS IN THE ANSWER BOOKLETThe symbols in this paper have their usual significancesEcTroN(A)(Answer ALL questions)

1. Write TRUE or f,'ALSE for each of the following statements. (7 marks)(a) Ionic compounds consist ofmolecules.(b) The mass of a given volume of gas varies with temperature.(c) The preparation of a standard solution of sulphuric acid cannot be done directly.(d) The negative ions are called anode.(e) Every oxidation must be accompanied by a corresponding reduction.(f) Ptyalin is a digestive en4rme in gastric juice.(g) When a substance is bumed in air heat is evolved.

2. Fi1l in the blanks with the correct word(s), pbrase(s), term(s), unit(s), etc., (7 marks)as necessary.(a) Anhydrous calcium chloride is used as a --------- agent in the laboratory.@) Zinc is used in al1oys such as ------.(c) Nitric acid is a colourless, ------ liquid.(d) All sulphides react with dilute sulphuric acid to give(e) Iodine dissolves in ethanol and ---:-, forming brown solutions.(f The presence of a --------- of electrons is characteristic of a base.(g) Tetraethyl-1ead is added to gasoline to prevent ----------.

3. Select the correct word(s), notation(s), term(s), unit(s), etc., given (7 marks)in the brackets.(a) Terylene is a I polyester ; polyamide ; polytetrafluoroethylene].(b) [Ionic ; Metallic ; Covalent] bonds are formed when non-rnetals react with one

another.(c) Ifthe constant contraction rate is continued, the volume ofthe gas will become zero

at l -273K ; -273"C ; 273K l.(d) A I bwette ; conical flask ; beaker ] is used to measure the amount ofa solution.(e) In the electrolysis of sodium hydroxide solution using platinum electrodes,I sodium is deposited ; oxygen is evolved ; hydrogen is evolved ] at the cathode.(f) The electrochemical reaction is a I catal]'tic ; reversible ; redox ] reaction.

(g) In the preparation of oxygen from KCIO:[ V:O5 ; Fe ; MnO2 ] can be used as cataiyst.lP.T.O.

7/29/2019 2013 ME Magway, Chemistry

2/4

)4. Match each of the items in List A with the appropriate items (7 marks)given in List B

List A List B(a) Potential energy (i) causes bums on the flesh(b) Sodium hydrogensulphate (ii) weak acid(c) Zrnc hydroxide (iii) made by the Leblance process(d) Calcium hydroxide (iv) amphoteric(e) Sulphwhioxide (v) due to the position ofbody(f) Liquid bromine (vi) slaked lime(g) Large pKa value (vii) absorbed in 98%H2SOa to form oleum5. Define the following:(a) Coordinate bond(b) Avogadro's theory(c) Law of conservation ofmass(d) Non-electroiyte(e) Reduction in term of hydrogen(f) Catalyst(g) Thermo chemical equations(h) Concentrated acid

(8 marks)

sEcTroN (B)6. Answer ALL questions (12 marks)(a) Draw the electron dot-cross structures of CIF: and NaCl.(b) Give the relation of Kelvin temperature and Celsius temperature.

What is meant by STP?(c) What happen when lead (II) oxide reacts with aqueous sodium hydroxide?

Give equation in words and symbols.(d) Write down the reactions at the cathode and anode for the electrolysis of aqueous

copper (II) sulphate soiution using platinum electrodes.(e) State which reactant is oxidized and which one is reduced in the following reaction.

Give reason for your answers.Fe + Clz ---+ FeClz

(f) Why does colnmon sall become damp when it is exposed to the air?

7/29/2019 2013 ME Magway, Chemistry

3/4

7. Answer any FIVE questions. (20 marks)(a) What mass of aluminium and copper will be liberated during eiectrolysis by i9300 C?( Cu= 63, Al=27, lF =96500C )(b) Balance the following equations by using either oxidation number method or ion-

electron method.(i) KzCrzOz + HI + HCIO+ ---------+ KCIO+ + Cr(ClOa)3 + Iz + HzO(i0H2SO3 + HNO:-+

HzSO4 +H2O+NO(c) An atom "X" has an atomic mrmber 9 whereas an atom "Y" has an atomic number 14.(i) Write down their complete electronic structures.(ii) Give their positions in the periodic table.

(iii)What tlpe of bond can be formed between X and Y ?(iv) Write down the formula of the compound formed between X and Y.

(d) Write equations in words and symbols for the following reactions.(i) Gold (IIi) chloride dissolved in excess of hydrochloric acid.(ii) Ammonium nitrate is decomposed by heat.

(e) The volume of a cerlain mass of gas occupies 968 cm3 at 515 mmHg. What is thevolume undff 768 mmHg at the same temperature ?

(f) (i) Give the typical composition and properties of stainless steel.(ii) Complete the following equations in symbols only.

Calcium carbonate r > ?Iron (lll) oxide + carbon monoxide zoor , ?(g) (i) State the '?hotochemical reaction".(ii) Using Le Chatelier's principle , predict the effect ofincreasing presswe on thefollowing equilibrium. Give reason for your answer.

Nzoq(g)ft) (i) What are the disadvantages for the production of common sait by the traditional

method?(ii) What are the sources ofplant nutrients and what does each ofthem supply to

plants?

lP.T.O.

7/29/2019 2013 ME Magway, Chemistry

4/4

48. Answer any FOUR questions. (32 marks)

(a) (i) Define " protogenic properties " and " conjugate base ".(ii) calculate the hydroxide ion concentrations having the pH value of 4.5 and thepOH value of 8.9.(b) (i) State *Hess's law of constant heat summation'and.. kinetic energy,,.(ii) Calculate the heat of formation of methanol, CH3OH O if its heat ofcombustion is -1247 kJ mol-r. The heats of formation of COz(g) and HzO(l) are

-393 kJ mol-r and -286 kJ mol-r, respectively.(c) (i) What happen when the cooked starch is treated with malt for t hour at 60oC?(ii) Outline an example to illustrate decolourization of bromine solution with an

alkene.(iii) How would you obtain propylene from n-propyl chloride?(iv) Discuss the reaction for chlorination ofmethylene chloride.(d) (i) How would you distinguish berween ethyl acetylene and dimethyl acetylene?(ii) A gas "B" is iiberated by passing propyne over heated sodium.

What is gas "B" ? Write down the chemical equation.(iii) Give the tlpes of four steps in the coal-fomring process.(iv) What are car exhaust fumes composed of ?(e) Give ar acco,nt on the manufacture of sulphwic acid by the contact process with a

labelled diagram.(f) Describe the laboratory preparation of ammonia with a suitable diagram.(g) How many cubic centimeters of lM hy&ochloric acid must be diluted with water tomake 1.5 dm3 of 0.25 M solution? lf 25 cm3 of sodium hydroxide neutralizes 22 cm3ofthis diluted solution, what is the molarity ofsodium hydroxide solution?(h) Discuss the extraction ofmagnesium from sea water.

**t ***** *********** * ******* !t*