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 anti-oxidants added to fat and oil containing food items?

To prevent oxidation

to increase oxidation

to prevent reduction

all 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

Sate the reactions exothermic or endothermic in nature: Dissolution of sodium hydroxide in water

endothermic reaction

both 1 & 3

exothermic reaction

all of these

7 / 15

State the reactions are exothermic or endothermic in nature: Dissolution of ammonium chloride in water

exothermic reaction

endothermic reaction

Both 1 & 2

none of these

8 / 15

On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed. Identify the brown gas X evolved.

X is nitrogen dioxide gas (NO<sub>2</sub>) that has evolved as brown, choking fumes

X is copper oxide gas that has evolved as brown, choking fumes

X is oxygen gas that has evolved as brown, choking fumes.

none of these

9 / 15

Which of the subsequent is (are) an endothermic process(es)?

Dilution of sulphuric acid

Sublimation of dry ice

Condensation of water vapours

Evaporation of water

1 and 2

2

3

2 and 4

10 / 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

11 / 15

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

Carbon dioxide or oxygen

Nitrogen or oxygen

Carbon dioxide or helium

Helium or nitrogen

12 / 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

13 / 15

When copper turning are added to silver nitrate solution, a blue coloured solution is formed after some time. It is because copper ?

Displaces silver from the solution

Forms a blue colored complex with AgNO₃

Is oxidized to Cu₂₊

Is reduced to Cu₂₊

14 / 15

The following reaction is used for the preparation of oxygen gas in the laboratory: 2KClO₃(s) Heat ⎯ → Catalyst ⎯⎯⎯ 2KCl(s) + 3O₂(g) Which of the following statement(s) is/are correct about the reaction?

It is a decomposition reaction and endothermic in nature

It is a combination reaction

It is a decomposition reaction and accompanied by release of heat

It is a photochemical decomposition reaction and exothermic in nature

15 / 15

One of the following processess doesnot require a chemical reaction:

Melting of candle wax when heated

Burning of candle wax when heated

Digestion of food in your stomach

Ripening of banana

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Science : Ch 01 – Chemical Reactions and Equations

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