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SECTION - I (40 marks)Compulsory : Attempt all questions from this section.

Question 1.(a) Match the following :

Write the number along side the corresponding letter. The first one has beendone for the you. The substances in the right-hand column can be used onlyonce.

(i) Drying agent A Formic acid

(ii) Polar molecule B Red lead(iii) Weak electrolyte C Hydrogen chloride(iv) Catenation D Sodium hydroxide(v) Thermal dissociation E Calcium chloride(vi) Oxidising agent F Ammonium chloride

G CarbonThe first answer is : (i) – E

(b) Write balanced equations for the following reactions.(i) Manganese (IV) oxide is heated with concentrated hydrochloric acid.(ii) Ethanol is heated with acetic acid.(iii) Aluminium oxide and sodium hydroxide.(iv) Sulphur is heated with concentrated nitric acid.(v) Catalytic oxidation of ammonia.

(c) Choose the correct answer from the choices A, B, C and D given.Write only the letter corresponding to the correct answer.

(i) Washing soda crystals areA. HygroscopicB. EfflorescentC. Deliquescent.D. Amphoteric.

(ii) The sulphide ore of zinc is concentrated byA. Electrolytic reduction.B. Reduction with coke.C. Froth flotation.D. Hydrolytic process.

(iii) If 100 ml of nitrogen gas contains X molecules at room temperature andpressure, then 200ml of nitrogen dioxide gas under the same conditionswill contain:A. X molecules.B. 2X molecules.C. 3X molecules.D. 0.5 X molecules.

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(iv) Formation of carbon tetrachloride from methane and chlorine is an exampleof :A. Hydrogenation.B. Dehydrogenation.C. Addition.D. Substitution.

(v) During the electrolysis of copper sulphate solution using inert electrodes:A. Copper is formed at the cathode and oxygen at the anode.B. Copper is formed at the anode and oxygen at the cathode.C. Copper is formed at the cathode and sulphur dioxide at the anode.D. The anode dissolves.

(d) Identify the following substances :(i) The alkane which is a green-house gas.(ii) The second member of the alkene series.(iii) The third member of the aldehyde series.(iv) The catalyst used in the hydrogenation of unsaturated hydrocarbons.(v) The main adulterating substance in spurious alcohol.

(e) State what you would observe in the following reactions.(i) A glass rod dipped in concentrated hydrochloric acid is introduced into a test

tube of ammonia.(ii) Acetylene is passed into ammoniacal cuprous chloride.(iii) Concentrated sulphuric acid is added to sugar.(iv) Nitrogen (II) oxide is mixed with air.(v) An aqueous solution of sodium hydrogen sulphate is tested with litmus paper.

(f) The equation for the action of heat on magnesium nitrate is:2Mg(NO3)2 2MgO + 4NO2 + O2

(i) How many moles of nitrogen dioxide are produced when one mole ofmagnesium nitrate decomposes?

(ii) What volume of oxygen at STP will be produced on heating 74g of magnesiumnitrate?

(iii) What is the mass of magnesium oxide formed when 74g of magnesium nitrateis heated?

(iv) Find out the mass of magnesium nitrate required to produce 5 moles ofgaseous products.

(v) Find out the mass of magnesium nitrate required to produce 44.8 litres ofnitrogen dioxide at STP.(Relative molecular mass of Mg(NO3)2= 148 and of MgO = 40)

(g) Name the organic compound prepared by each of the following Reactions(i) CaC2 + H2O (ii) C2H5Br + alcoholic KOH (iii) CH3COONa + NaOH (iv) C2H5Br + aqueous KOH (v) C2H4 + H2O

(h) Give reasons for the following:(i) Covalent compounds have low boiling point.(ii) Solid sodium chloride does not conduct electricity.(iii) Powdered coke is sprinkled on top of the electrolyte in the extraction of

aluminium.

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(iv) Ionisation potential decreases down a group in the periodic table.(v) Aluminium is used in thermite welding.

SECTION - II(Attempt any four questions)

Question 2.(a) Study the diagram given below and answer the questions that follow :

(i) Name the chemicals A (solid) and B (liquid).(ii) Write a balanced equation for the reaction which occurs in the flask.(iii) What is the special feature of the apparatus used? State the reason.(iv) Explain what would happen to the nitric acid formed if the retort flask is

heated very strongly.

(b) Draw and name different isomers having the molecular formula :(i) C4H10(ii) C4H8

(c) Name a non-metal which :(i) Has a metallic lustre.(ii) Is a liquid at room temperature.(iii) Is a good conductor of electricity.(iv) Forms two types of oxides.

Question 3.(a) Write balanced equations to show how the following salts can be prepared.(i) Sodium sulphate.(ii) Iron (II) sulphate.(iii) Lead sulphate from lead oxide.

(b) The atomic numbers of three elements A, B and C are 6, 11 and 17 respectively.(i) State the period and group of the periodic table where element A belongs.(ii) Name another element in the periodic table which exhibits similar

properties to that of element C.(iii) Among the element A, B and C which is the strongest oxidising agent?(iv) What type of bonding occurs when elements A and C combine?

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Heat

Nitricacid

Cold water

Sandy tray

A+ B

Glass retort

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(c) Classify the following substances into strong electrolyte, weak electrolyteor non-electrolyte.

(i) Carbon tetrachloride.(ii) Carbonic acid.(iii) Ammonium hydroxide.(iv) Potassium chloride solution.

From the list given above pick out the substance which contains only ionsand write the formula of all the ions present.

Question 4.(a) During purification of copper – State : i) The anode used ii) The electrolyte

used. Write the equation taking place at the anode in the above.

(b) Sulphur dioxide is converted to sulphur trioxide on large scale.(i) Write a balanced equation to show the production of sulphur dioxide from

iron pyrites.(ii) State the optimum temperature required for the conversion of sulphur

dioxide to sulphur trioxide.(iii) Name the catalyst that is used in this conversion. State two reasons why

the catalyst you have named is preferred to any other.

(c) State Gay-Lussac’s law of combining volumes.

(d) Write equations to show the reaction of copper with :(i) Cold and dilute nitric acid.(ii) Hot and concentrated nitric acid.

Question 5.(a) Give the electron dot structures of the following:(i) H3O

+

(ii) CH4

(b) Give a chemical test to distinguish between the following pairs of compoundsusing sodium hydroxide solution.

(i) Aqueous iron (II) chloride and aqueous iron (III) chloride.(ii) Solid ammonium chloride and solid magnesium chloride.

(c) Classify the following as oxidation or reduction reactions. Also completethe reactions.

(i) Ni Ni2+

(ii) Fe3+ Fe2+

(iii) O2- O

(d) Among the elements in the third period of the periodic table, name thefollowing:

(i) The most electronegative element.(ii) The element with zero electron affinity.(iii) The element with the largest atomic radius.(iv) The element with the lowest ionisation energy.

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Question 6.(a) A compound has the following percentage composition by mass:

Carbon = 54.55%, Hydrogen = 9.10% and Oxygen = 36.26%Its vapour density is 44. Determine the molecular formula of the compound.(Atomic mass : C = 12, H = 1, O = 16)

(b) (i) What are the differences between hydrogen chloride and ammonia withrespect to the following:1. Suitable drying agent.2. Method of collecting the gas.

(ii) Write the balanced chemical equation for : Action of hydrochloric acid onsodium bicarbonate.

(c) Write balanced equations to show the reaction of dilute hydrochloric acidwith:

(i) Sodium sulphide(ii) Sodium thiosulphate.

(d) What is the composition of aqua regia?

Question 7.(a) Refer to the flowchart below and answer the questions that follow:

CuSO4A Cu B CuO C CuSO4

D E

Cu (OH)2

Write balanced equations for the conversions A to E.

(b) The equation 4NH3 + 5O2 4NO + 6H2O, represents the catalytic oxidation ofammonia. If 100 cm3 of ammonia is used, calculate the volume of oxygen requiredto oxidize the ammonia completely.

(c) (i) Name the main ore of iron.(ii) Name the most important alloy of iron.(iii) State two significant properties possessed by this alloy.

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