Important Questions (1 mark): Chemical Reactions And Equations


20 Questions MCQ Test Science Class 10 | Important Questions (1 mark): Chemical Reactions And Equations


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This mock test of Important Questions (1 mark): Chemical Reactions And Equations for Class 10 helps you for every Class 10 entrance exam. This contains 20 Multiple Choice Questions for Class 10 Important Questions (1 mark): Chemical Reactions And Equations (mcq) to study with solutions a complete question bank. The solved questions answers in this Important Questions (1 mark): Chemical Reactions And Equations quiz give you a good mix of easy questions and tough questions. Class 10 students definitely take this Important Questions (1 mark): Chemical Reactions And Equations exercise for a better result in the exam. You can find other Important Questions (1 mark): Chemical Reactions And Equations extra questions, long questions & short questions for Class 10 on EduRev as well by searching above.
QUESTION: 1

Which of the following are exothermic reactions?

(i) Burning of coal.

(ii) Reaction of water with quicklime.

(iii) Respiration.

(iv) Evaporation of water.

Solution:

Only evaporation of water is an endothermic reaction.

QUESTION: 2

In the balanced equation

a Fe2O3 + b H2 → c Fe + d H2O

The values of a, b, c and d are the respectively:

Solution:

The balanced reaction can be written as follow:
Fe2O3 + 3H2 → 2Fe + 3H2O
Thus,
a→1, b→3, c→2, d→3.

QUESTION: 3

Carbon dioxide turns lime water milky due to the formation of:

Solution:

Ca(OH)2(aq) + CO2 → CaCO3(s) + H2O
Lime turns water turns milky

QUESTION: 4

When a solution of barium chloride in water is added to an aqueous solution of sodium sulphate, the following happens:

Solution:

When barium chloride solution is added to sodium sulphate solution, then a white precipitate of barium sulphate is formed along with sodium chloride solution.
BaCl2 (aq) + Na2SO4(aq) → BaSO4 (s) + 2NaCl(aq)

QUESTION: 5

The process of reduction involves ______.

Solution:

The process of reduction involves gain of electrons.

QUESTION: 6

In the reaction: 3MnO2 + 4Al → 3Mn + 2Al2O3
The oxidising agent is:

Solution:

MnO2 loses oxygen and therefore, gets reduced. Hence, it acts as an oxidising agent.

QUESTION: 7

When magnesium ribbon is burnt in air, the ash formed is:

Solution:

Ash is white powder of magnesium oxide.

QUESTION: 8

The gas produced on addition of dilute sulphuric acid on powdered zinc is:

Solution:

Zn + H2SO4(dil) → ZnSO4 + H2

QUESTION: 9

When in the blue solution of copper sulphate, zinc strip is dipped, after some time the colour changes to:

Solution:

Zn + CuSO4(aq) → Cu + ZnSO4
Blue Colourless

QUESTION: 10

In the reaction: SO2(g) + 2H2S(g) → 2H2O(l) + S (s)
The reducing agent is:

Solution:

H2S gets oxidised and hence it is a reducing agent.

QUESTION: 11

A white precipitate can be formed when dil H2SO4 is added to aqueous solution of:

Solution:

BaCl2(aq) + H2SO4(aq) → BaSO4(s) + 2HCl(aq)
white ppt.

QUESTION: 12

When a solution of barium chloride in water is added to an aqueous solution of sodium sulphate, the following happens :

Solution:

BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq)
white ppt

QUESTION: 13

The formula of rust is:

Solution:

Rust is Fe3O3. x H2O

QUESTION: 14

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 following can be used in place of lead nitrate?

Solution:

Pb(CH3COO)3 + 3KI → PbI3 + 3CH3COOK

QUESTION: 15

Which one of the following four metals would be displaced from the solution of its salt by other three metals ?

Solution:

Silver because it is the least reactive among these metals.

QUESTION: 16

Which is the reducing agent in the reaction ?

ZnO + C → Zn + CO

Solution:

C gets oxidised to CO and hence is a reducing agent.

QUESTION: 17

The values of a, b, c and d in the balanced chemical equation, a BaCl2 + b Al2(SO4)3 → c AlCl3 + d BaSO4 are:

Solution:

3BaCl2 + Al2(SO4)3 → 2AlCl3 + 3BaSO4

QUESTION: 18

The formulae of quick lime and limestone are respectively:

Solution:

Quick lime is CaO and limestone is CaCO3.

QUESTION: 19

............ is a process in which there is loss of electrons.

Solution:

Oxidation is a process that involves the loss of electrons.

QUESTION: 20

Which of the following statements about the given reaction are correct?
3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g)

(i) Iron metal is getting oxidised
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as oxidising agent

Solution:

The substance which oxidises the other substance is called oxidising agent. So, water is an oxidising agent.