CBSE Board Half Yearly Exam Question Paper Class-X Chemistry Assignment 2022

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CBSE Board Half Yearly Exam Question Paper Class-X Chemistry Assignment 2022

ABC School

Class – X

Chemistry

CBSE Board Half Yearly Exam Exam Sample Paper

Assignment

MCQ

Q1 In the decomposition of lead (II) nitrate to give lead (II) oxide, nitrogen dioxide, and oxygen gas, the coefficient of nitrogen dioxide (in the balanced equation) is

(a) 1

(b) 2

(d) 4

Q2 Fatty foods become rancid due to the process of

(a) oxidation

(b) corrosion

(d) hydrogenation

Q3 We store silver chloride in a dark coloured bottle because it is

(a) a white solid

(b) undergoes redox reaction

(d) none of the above

Q4 Silver article turns black when kept in the open for a few days due to the formation of

(a) H2S

(b) AgS

(d) Ag2S

Q5 ) Which of the following oxides of iron would be obtained on the prolonged reaction of iron with steam?

a) FeO

b) Fe2O3

c) Fe3O4

d) Fe2O3 and Fe3O4

Q6 The arrangement for Copper, Tin, Lead, and Mercury, according to the reactivity series is:

a) Tin> Lead> Copper> Mercury

b) Lead> Copper> Mercury> Tin

c) Copper> Mercury> Tin> Lead

d) Mercury> Tin> Lead> Copper

Q7) What happens when a pellet of sodium is dropped in water?

(a) It catches fire and forms oxide.

(b) It absorbs heat and forms oxide.

(d) It absorbs heat and forms hydroxide.

Q8 Match the acids given in Column (A) with their correct source given in Column (B)

Column A	Column B
Lactic acid	Tomato
Acetic acid	Lemon
Citric acid	Vinegar
Oxalic acid	Curd

Q9 Match the important chemicals given in Column (A) with the chemical formulae given in Column (B).

Column A	Column B
Plaster of Paris	Ca(OH)2
Gypsum	CaSO4.½ H2O
Bleaching Powder	CaSO4. 2 H2O
Slaked Lime	CaOCl2

Q10 Aqua regia is a freshly prepared mixture of concentrated HNO3 and concentrated HCl in the ratio of:

a) 1:3 respectively

b) 2:3 respectively

c) 3:1 respectively

d) 3:2 respectively

ASSERTION REASON QUESTIONS

The following questions consist of two statements – Assertion (A) and Reason (R). Answer these questions by selecting the appropriate option given below:

(a) Both A and R are true and R is the correct explanation of A.

(b) Both A and R are true but R is not the correct explanation of A.

(d) A is false but R is true.

Q.1. Assertion (A): The decomposition of vegetable matter into compost is an example of exothermic reactions.

Reason (R): Exothermic reactions are those reactions in which heat is evolved.

Q.2. Assertion (A): When HCl is added to zinc granules, a chemical reaction occurs.

Reason (R): The evolution of a gas and change in colour indicate that the chemical reaction is taking place.

Q3 Assertion (A) : In a reaction of copper with oxygen, copper serves as a reducing agent.

Reason (R) : The substance which gains oxygen in a chemical reaction acts as a reducing agent.

Q4 Assertion (A): Iron articles are painted so as to prevent them from rusting.

Reason (R): When the surface of iron is coated with paint, its surface does not come in contact with oxygen and moisture therefore rusting does not take place.

Q5 Assertion (A): Copper sulphate crystals are wet because it contains water of crystallization.

Reason (R): Water of crystallization is the fixed number of molecules of water present in one formula unit of salt.

Q6 Assertion (A): The aqueous solutions of glucose and alcohol do not show an acidic character.

Reason (R): Aqueous solutions of glucose and alcohol do not give H+ ions.

Q7 Assertion (A) : HCl gas does not change the colour of dry blue litmus paper.

Reason (R) : HCl gas dissolves in the water present in wet litmus paper to form H+ ions.

Q8 Assertion (A): Zinc becomes dull in moist air.

Reason (R) : Zinc is coated by a thin film of its basic carbonate in moist air.

SUBJECTIVE QUESTIONS

Q1 What is observed when carbon dioxide gas is passed through lime water

(i) for a short duration?

(ii) for a long duration? Also, write the chemical equations for the reactions involved.

Q2 Write the names of the product formed when zinc reacts with NaOH. Also, write the balanced chemical equation for the reaction involved. Write a test to confirm the presence of the gas that evolved during this reaction.

Q3 Cloth strip dipped in onion juice is used for testing a liquid ‘X. The liquid ‘X changes its odour. Which type of indicator is onion juice? The liquid ‘X turns blue litmus red. List the observations the liquid ‘X will show on reacting with the following :

(a) Zinc granules

(b) Solid sodium carbonate

Write the chemical equations for the reactions involved.

Q4 Complete and balance the following chemical equations :

(i) NaOH(aq) + Zn(s) →

(ii) CaCO3(s) + H2O(l) + CO2(g) →

(iii) HCl(aq) + H2O(l) →

Q5 Name one metal and one non-metal that exist in the liquid state at room temperature. Also, name two metals having a melting point of less than 310 K (37°C)

Q6 A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black colour product. Identify M and black coloured products and explain M’s reaction with oxygen.

Q7 Identify the oxidizing agent (oxidant) in the following reactions

(a ) Pb3O4 + 8 HCI → 3 PbCl2 + Cl2 + 4 H2O

(b ) 2 Mg + O2 → 2 MgO

(c ) CuSO4 + Zn → Cu + ZnSO4

(d ) V2O5 + 5 Ca → 2 V + 5 CaO (e ) 3 Fe + 4 H2O → Fe3O4 + 4 H2 (f ) CuO + H2 → Cu + H2O

Q8 Balance the following chemical equations and identify the type of chemical reaction.

(a ) Mg (s) + Cl2 (g) → MgCI2 (s)

(b ) HgO (s) + Heat → Hg (l) + O2 (g)

(c ) Na (s) + S (s) → Na2S (s)

(d ) TlCl4 (l) + Mg (s) → Tl (s) + MgCl2 (s) (e ) CaO (s) + SiO2 (s) → CaSiO3 (s) (f ) H2O2 (l) + UV → H2O (l) + O2 (g)

Q9 A white precipitate is obtained by adding a barium chloride drop to an aqueous sodium sulphate solution.

(a ) Write a balanced chemical equation of the reaction involved