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

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

3 / 15

Mention whether it is a physical or chemical changes: -Evaporation of petrol

physical

chemical

Both 1 & 2

none of these

4 / 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

5 / 15

Mention whether it is physical or chemical changes :Curdling of milk

chemical

physical

Both 1 & 2

none of these

6 / 15

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

Hydrogen

H₂O

Oxygen

both 1 & 3

7 / 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

8 / 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

9 / 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

10 / 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

11 / 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₊

12 / 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

13 / 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

14 / 15

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

Displacement reaction

Precipitation reaction

Combination reaction

Double displacement reaction

1

2

4

2 and 4

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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