Chemical Reaction And Equation - class 10 MCQ

 

Important MCQS : Chemical Reaction and Equation .  It is most important topic of NCERT  Chemical Reaction and Equation chapter 1  in Class 10.  Questions are frequently asked in the CBSE  board ,   ICSE Board and other competitive exam ( IIT JEE, NEET,  AIMS, State Engineering exam ) from “mcqs on Chemical Reaction and Equation multiple choice questions “.

Chemical Reaction and Equation question bank will be very beneficial for the students who are engaged in the preparation of  upcoming board exam and other competitive exam .

Chemical Reaction and Equation class 10 MCQ online test

Q1.  Chemically rust is -

(a)  hydrated ferrous oxide

(b)  only ferric oxide

(c)  hydrated ferric oxide

(d)  none of these

 

Ans-  (c)  hydrated ferric oxide

 

Q2.  Which of the following gases can be used for storage of fresh sample  of an oil for a long time?

(a)  Carbon dioxide or oxygen

(b)  Nitrogen or helium    

(c)  Helium or oxygen

(d)  Nitrogen or oxygen

 

Ans -  (b)  Nitrogen or helium    

 

Q3.  The electrolytic decomposition of water gives H₂ and O₂ in the ratio of

(a)  1 : 2 by volume

(b)  2 : 1 by volume

(c)  8 : 1 by mass

(d)  1 : 2 by mass

 

Ans -  (b)   2 : 1 by volume

 

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

(a)  H₂S

(b)  AgS

(c)  AgSO₄

(d)  Ag₂S

 

Ans-  (d)  Ag₂S

 

Q5. When ferrous sulphate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in colour from:

 a. Blue to green.

 b. Green to blue.

 c. Green to brown.

 d. Green to yellow.

 

Ans- c.    Green to brown

 

Q6. Which of the following gases is used in the storage of fat and oil containing foods for a long time?

 a. Carbon di oxide gas

 b. Nitrogen gas

 c. Oxygen gas

 d. Neon gas 

 

Ans- b.    Nitrogen gas

 

Q7. The displacement reaction between iron (III) oxide and a metal X is used for welding the rail tracks. Here X is:

 a. Copper granules

 b. Magnesium ribbon

 c. Sodium pellets

 d. Aluminium dust

 

Ans-  d.  Aluminium dust

 

Q8. The neutralization reaction between an acid and a base is a type of:

 a. Double displacement reaction

 b. Displacement reaction

 c. Addition reaction

 d. Decomposition reaction

 

Ans- a.    Double displacement reaction

 

Q9- Reaction of ‘magnesium’ with air is

A) Exothermic reaction

B) Endothermic reaction

C) Reversible reaction

D) Substitution reaction

 

Ans – ( A) Exothermic reaction

 

Q10- What chemicals are used in fireworks?

A) Copper chloride

B) Calcium chloride

C) Barium chloride

D) All of above

 

 Ans –  (D) All of above

 

Q11- When a magnesium ribbon is burnt in air, the ash formed is

A) Black

B) White

C) Yellow

D) Pink

 

Ans –  ( B) White

 

Q12- Color of magnesium oxide is

A) White

B) Blue

C) Grey

D) Pink

 

Ans –  (A) White

 

Q13- If magnesium is gently heated, it forms

A) Magnesium oxide

B) Magnesium sulfide

C) Magnesium nitrite

D) Magnesium carbonate

 

Ans –  (A) Magnesium oxide

 

Q14- When carbon dioxide is passed through lime water,

A) Calcium hydroxide is formed

B) White precipitate of CaO is formed

C) Lime water turns milky

D) Color of lime water disappears.

 

 Ans –  (C) Lime water turns milky

 

Q15- When crystals of lead nitrate are heated strongly in a dry test tube

A) Crystals immediately melt

B) A brown residue is left

C) White fumes appear in the tube

D) A yellow residue is left

 

 Ans –  (B) A brown residue is left

 

Q16- Color of Solid magnesium is

A) Dark grey

B) Silver grey

C) Black

D) Whitish silver

 

Ans –  (B) Silver grey

 

Q17- Consider equations:

Ca⁺²(aq) + 2OH‾(aq)→Ca(OH)₂ (s). Precipitate of calcium hydroxide will be of

A) Green color

B) Blue color

C) Brown color

D) White color

 

Ans –  (D) White color

 

Q18- Which of the given statements is not a physical change?

A) Boiling of water to give water vapour

B) Melting of ice to give water

C) Dissolution of salt in water

D) Combustion of Liquefied Petroleum Gas (LPG)

 

Ans -  ( D) Combustion of Liquefied Petroleum Gas (LPG)

 

Q19- An element X on exposure to moist air turns reddish-brown and a new compound Y is formed. The substances X and Y are

A) X = Fe, Y = Fe₂O₃

B) X = Ag, Y = Ag₂S

C) X = Cu, Y = CuO

D) X = Al, Y = Al₂O₃

 

 Ans -  ( A)     X = Fe,  Y = Fe₂O₃

 

Q20- The reaction of H₂ gas with oxygen gas to form water is an example of

A) Combination reaction

B) Redox reaction

C) Exothermic reaction

D) All of these reactions.

 

 Ans -  ( A) Combination reaction

 

Q21- Rancidity can be prevented by

A) Adding antioxidants

B) Storing food away from light

C) Keeping food in refrigerator

D) All of these

 

 Ans -  ( D)  All of these

 

Q22- In which of the given, heat energy will be evolved?

A) Electrolysis of water

B) Dissolution of NH₄Cl in water

C) Burning of L.P.G.

D) Decomposition of AgBr in the presence of sunlight

 

 Ans -   (C) Burning of L.P.G.

 

Q23- Dilute hydrochloric acid is added to granulated zinc taken in a test tube. The following observations are recorded. Point out the correct observation.

A) The surface of metal becomes shining

B) The reaction mixture turns milky

C) Odour of a pungent smelling gas is recorded

D) A colorless and odourless gas is evolved

 

Ans -   ( D)  A colorless and odourless gas is evolved

 

Q24- Consider reaction is an example of

4NH₃ (g) + 5O₂ (g) → 4NO (g) + 6H₂O (g)

(a). Displacement reaction,

(b) Combination reaction

(c) Redox reaction

(d) Neutralization reaction.

A) (A) & (D)

B) (B) & (C)

C) (A) & (C)

D) (C) & (D)

 

 

 

Q25- Which of the following statements about the given reaction are correct?

 3Fe(s) + 4H₂O(g) → Fe₃O₄ (s) + 4H₂ (g)

(a) Iron metal is getting oxidized.

(b) Water is getting reduced.

(c) Water is acting as reducing agent.

(d)Water is acting as oxidizing agent.

A) (A), (B) & (C)

B) (C) & (D)

C) (A), (B) & (D)

D) (B) & (D)

 

Ans -  (C)     (A), (B) & (D)

 

Q26- Which of the following are exothermic processes?

(a) Reaction of water with quick lime

(b) Dilution of an acid

(c) Evaporation of water

(d) Sublimation of camphor (crystals)

A) (A) & (B)

B) (B) & (C)

C) (A) & (D)

D) (C) & (D)

 

 Ans-   ( A)    (A) & (B)

 

Q27- A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple color of the solution fades and finally disappears. Which of the given equation is the correct explanation for the observation?

A) KMnO₄ is an oxidizing agent, it oxidizes FeSO₄

B) FeSO₄ acts as an oxidizing agent and oxidizes KMnO₄

C) The color disappears due to dilution, no reaction is involved

D) KMnO₄ is an unstable compound and decomposes in the presence of FeSO₄ to a colourless compound

 

Ans-   (A)   KMnO₄ is an oxidizing agent, it oxidizes FeSO₄

 

Q28- Which among the following statement(s) is /are true? Exposure of silver chloride to sunlight for a long duration turns grey due to-

(a) The formation of silver by decomposition of silver chloride.

(b) Sublimation of silver chloride.

(c) Decomposition of chlorine gas from silver chloride.

(d) Oxidation of silver chloride.

A) Only (A)

B) (A) & (C)

C) (B) & (C)

D) Only (D)

 

 Ans -  ( A)   Only (A)

 

Q29- Solid calcium Oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form its solution called lime water. Which among the following is are true about slaking of lime and the solution formed?

(a) It is an endothermic reaction.

(b) It is exothermic reaction.

(c) The pH of the resulting solution will be more than seven.

(d) The pH of the resulting solution will be less than seven.

A) (A) & (B)

B) (B) & (C)

C) (A) & (D)

D) (C) & (D)

 

 Ans-  (B)    (B) & (C)

 

Q30- Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?

(a) Displacement reaction

(b) Precipitation reaction

(c) Combination reaction

(d) Double displacement reaction

A) Only (A)

B) Only (B)

C) Only (D)

D) (B) & (D)

 

 Ans –  ( D)     (B) & (D)

 

Q31- Which of the following is (are) an endothermic process(es)?

(a) Dilution of sulphuric acid

(b) Sublimation of dry ice

(c) Condensation of water vapours

(d) Evaporation of water

A) Both (A) & (C)

B) Only (B)

C) Only (C)

D) Both (B) & (D)

 

 Ans -  ( D) Both (B) & (D)

 

Q32- In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the given can be used in place of lead nitrate?

A) Lead sulphate (insoluble)

B) Lead acetate

C) Ammonium nitrate

D) Potassium sulphate

 

 Ans-  ( B) Lead acetate

 

Q33- Which of the given gases can be used for storage of fresh sample of an oil for a long time?

A) Carbon dioxide or oxygen

B) Nitrogen or oxygen

C) Carbon dioxide or helium

D) Helium or nitrogen

 

 Ans-  (D) Helium or nitrogen

 

Q34- Fatty foods become rancid due to the process of ________

A) Oxidation

B) Corrosion

C) Reduction

D) Hydrogenation

 

 Ans-   (A)  Oxidation

 

Q35- Which information is not conveyed by a balanced chemical equation?

A) Physical states of reactants and products

B) Symbols and formulae of all the substances involved in a particular reaction

C) Number of atoms/molecules of the reactants and products formed

D) Whether a particular reaction is actually feasible or not

 

 Ans-  ( D) Whether a particular reaction is actually feasible or not

 

Q36- The chemical formula of lead sulphate is

A) Pb₂SO₄

B) Pb(SO₄)₂

C) PbSO₄

D) Pb₂(SO₄)₃

 

 Ans-  ( C) PbSO₄

 

Q37- Chemically, rust is

A) Hydrated ferrous

B) Only ferric oxide

C) Hydrated ferric oxide

D) None of these

 

 Ans-   (C) Hydrated ferric oxide

 

Q38- Both CO₂ and H₂ gases are

A) Heavier than air

B) Colourless

C) Acidic in nature

D) Soluble in water

 

 Ans -  ( B) Colourless

 

 

Q39- 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

C) 3

D) 4

 

 Ans -  ( D)  4

 

Q40- We store silver chloride in a dark coloured bottle because it is

A) A white solid

B) Undergoes redox reaction

C) To avoid action by sunlight

D) None of the above

 

 Ans-  (C) To avoid action by sunlight

 

Q41- Silver article turns black when kept in the open for a few days due to formation of

A) H₂S

B) AgS

C) AgSO₄

D) Ag₂S

 

 Ans –(D)  Ag₂S

 

Q42.  When crystals of lead nitrate are heated strongly in a dry test tube

(a)  crystals immediately melt

(b)  a brown residue is left    

(c)  white fumes appear in the tube

(d)  a yellow residue is left

 

Ans-  (b)  a brown residue is left    

 

Q43.  Dilute hydrochloric acid is added to granulated zinc taken in a test tube. The following observations are recorded. Point out the correct observation.

(a)  The surface of metal becomes shining    

(b)  The reaction mixture turns milky   

 (c)  Odour of a pungent smelling gas is recorded   

 (d)  A colourless and odourless gas is evolved

 

Ans- (d)   A colourless and odourless gas is evolved

 

Q44.  When a magnesium ribbon is burnt in air, the ash formed is

(a)  black

(b)  white

(c)  yellow

(d)  pink

 

Ans -  (b)  white

 

Q45- Consider equation:

Pb⁺² (aq) + 2OH⁻ (aq) → Pb(OH)₂ (s). precipitate of lead (II) hydroxide will be of

A) Green color

B) Blue color

C) Brown color

D) White color

 

Ans –  (D) White color

 

Q46- Consider equation:

Cu⁺² (aq) + 2OH⁻(aq) → Cu(OH)₂ (s). precipitate of Copper Hydroxide (Cu(OH)₂) will be of

A) Green color

B) Blue color

C) Brown color

D) White color

 

 Ans –  (B) Blue color

 

Q47- Consider reaction: Na(s) + O₂(g) → Na₂O(s). Moles of sodium needed to balance equation would be

A) 1

B) 2

C) 3

D) 4

 

Ans –  ( D) 4

 

Q48- Consider reaction: S(s) + O₂(g) → SO₂. state of SO₂ in this reaction is

A) Liquid

B) Solid

C) Gaseous

D) All Three

 

Ans –  (C) Gaseous

 

Q49- Which one of the given processes involves chemical reactions?

A) Storing of oxygen gas under pressure in a gas cylinder

B) Keeping petrol in a China dish in the open

C) Liquefaction of air

D) Heating copper wire in the presence of air at high temperature

 

Ans – (D) Heating copper wire in the presence of air at high temperature

 

Q50- On immersing an iron nail in CuSO₄ solution for a few minutes, you will observe

A) No reaction takes place

B) The color of solution fades away

C) The surface of iron nails acquire a black coating

D) The color of solution changes to green

 

 Ans -   ( D) The color of solution changes to green

 

Q51.  In which of the following, heat energy will be evolved?

(a)  Electrolysis of water    

(b)  Dissolution of NH₄Cl in water   

 (c)  Burning of L.P.G.    

(d)  Decomposition of AgBr in the presence of sunlight

 

Ans -  (c)  Burning of L.P.G.    

 

Q52. Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:

 a. Make the ribbon surface shinier

 b. Remove the layer of magnesium oxide from the ribbon surface

 c. Remove the layer of magnesium carbonate from the ribbon surface

 d. Remove the moisture from the ribbon surface

 

Ans-  c.   Remove the layer of magnesium carbonate from the ribbon surface.

 

Q53.  In a chemical reaction between sulphuric acid and barium chloride solution the white precipitates formed are of:

 a. Hydrochloric acid

 b. Barium sulphate

 c. Chlorine

 d. Sulphur

 

Ans -  b.    Barium sulphate

 

Q54. The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy, is a kind of:

 a. Exothermic process

 b. Endothermic process

 c. Reversible process

 d. Physical process

 

Ans-  a.    Exothermic process

 

Q55.  A chemical reaction does not involve:

 a. Formation of new substances having entirely different properties than that of the  reactants

 b. Breaking of old chemical bonds and formation of new chemical bonds

 c. Rearrangement of the atoms of reactants to form new products

 d. Changing of the atoms of an element into those of another element to form new  products

 

Ans-  d.     Changing of the atoms of an element into those of another element to form new  products

 

Q56. One of the following processes does not involve a chemical reaction. That is:

 a. Melting of candle wax when heated

 b. Burning of candle wax when heated

 c. Digestion of food in our stomach

 d. Ripening of banana

 

Ans- a.     Melting of candle wax when heated

 

Q57. It is necessary to balance a chemical equation in order to satisfy the law of:

 a. Conservation of motion

 b. Conservation of momentum

 c. Conservation of energy

 d. Conservation of mass

 

Ans-  d.    Conservation of mass

 

Q58. All the methods mentioned below can be used to prevent the food from getting rancid except:

 i. Storing the food in the air-tight containers

 ii. Storing the food in refrigerator

 iii. Keeping the food in clean and covered containers

 iv. Always touching the food with clean hands

  a. (i) and (ii)

  b. (i) and (iii)

  c. (i), (iii) and (iv)

  d. (iii) and (iv) 

 

Ans-  d.   (iii) and (iv) 

 

Q59. Rusting of iron involves a chemical reaction which is a combination of:

 a. Reduction as well as combination reactions

 b. Oxidation as well as combination reactions

 c. Reduction as well as displacement reactions

 d. Oxidation as well as displacement reactions

 

Ans- b.    Oxidation as well as combination reactions

 

Q60- When crystals of lead nitrate are heated strongly in a dry test tube

A) Crystals immediately melt

B) A brown residue is left

C) White fumes appear in the tube

D) A yellow residue is left

 

 Ans –  ( B)  A brown residue is left

 

Q61- Which of the given products is formed when calcium oxide reacts with water?

A) Slaked lime

B) Carbon dioxide

C) Calcium oxide

D) Oxygen gas

 

 Ans –  (A)  Slaked lime

 

Q62- What is the other name for quick lime?

A) Calcium hydroxide

B) Calcium oxide

C) Carbon dioxide

D) Sodium oxide

 

Ans –  (B)  Calcium oxide

 

Q63- What is the chemical name for slaked lime?

A) Calcium carbonate

B) Calcium oxide

C) Calcium hydroxide

D) Carbon monoxide

 

Ans –  (C)  Calcium hydroxide