Science : Ch 01 – Chemical Reactions and Equations

Science : Ch 01 - Chemical Reactions and Equations

This test is designed based on NCERT Syllabus for Class 10 Topics : Chemical Reactions and Equations

Each time random 15 questions will be displaced
So retake the quiz till you have mastered all the questions

1 / 15

Why are oil and fat containing food items fushed with nitrogen while packing?

to prevent reduction

To prevent rancid

to increase oxidation

none of these

2 / 15

Identify the reducing agent in the following reactions: Fe₂O₃ + 3CO → 2Fe + 3CO₂

CO

Fe

CO₂

Fe₂O

3 / 15

When hydrogen sulphide gas is passed through a blue solution of copper sulphate, the colour of the solution fades and a black precipitate is obtained.Name the type of reaction taking place.

double displacement reaction

single displacement reaction

double replacement reaction

all of these

4 / 15

When hydrogen sulphide gas is passed through a blue solution of copper sulphate, the colour of the solution fades and a black precipitate is obtained.Why does the colour of the solution fades?

due to its reaction with hydrogen sulphide gas and results into the formation of colourless solution of sulphuric acid.

due to its reaction with Copper sulphate gas and results into the formation of colourless solution of sulphuric acid.

Both 1 & 2

all of these

5 / 15

When hydrogen sulphide gas is passed through a blue solution of copper sulphate, the colour of the solution fades and a black precipitate is obtained.Write the chemical name of the black precipitate formed.

hydrogen sulphide

copper sulphide.

hydrogen sulphate

none of these

6 / 15

Mention whether it is physical or chemical changes : Heating of an iron rod to red hot

physical

chemical

Both 1 & 2

none of these

7 / 15

Mention whether it is physical or chemical changes: Sublimation of solid ammonium chloride

physical

chemical

Both 1 & 2

none of these

8 / 15

State the reactions exothermic or endothermic in nature: Dilution of sulphuric acid

endothermic reaction

exothermic reaction

Both 1 & 2

none of these

9 / 15

In the electrolysis of water, name the gases liberated at cathode

Hydrogen

H₂O

Oxygen

both 1 & 3

10 / 15

Which of the following is not a physical change?

Boiling of water to give water vapour

Melting of ice to give water

Dissolution of salt in water

Combustion of Liquefed Petroleum Gas

11 / 15

Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during the electrolysis of water is:

1:01

2:01

4:01

1:02

12 / 15

Which of the following reactions is an endothermic reaction?

Burning of coal.

Decomposition of vegetable matter into compost

Process of respiration.

Decomposition of calcium carbonate to form quick lime and carbon dioxide

13 / 15

When hydrogen sulphide gas is passed through a blue solution of copper sulphate a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remain in the solution. The reaction is an example of a:

Combination reaction

Displacement reaction

Decomposition reaction

Double displacement reaction

14 / 15

One of the following does not happen during a chemical reaction.

Breaking of old chemical bonds and formation of new chemical bonds

Formation of new substances with entirely diferent properties

Atoms of one element change into those of another element to form new products

A rearrangement of atoms takes place to form new products

15 / 15

Which of the following are combination reactions?

KClO₃ →^(Heat)→ 2KCl + 3O₂

MgO + H₂O → Mg(OH)₂

4Al + 3O₂ → 2Al2O₃

Zn + FeSO₄ →ZnSO₄ + Fe

1 and 4

3 and 4

2 and 4

2 and 3

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Science : Ch 01 – Chemical Reactions and Equations

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