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

Which reaction takes place when layer of silver deposit on copper wire when dipped in silver nitrate solution?

displacement reaction

replacement reaction

oxidation

reduction reaction

2 / 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

3 / 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

4 / 15

Identify the reducing agent in the following reactions 4NH₃ + 5O₂ → 4NO + 6H₂O

O₂

NH₃

NO

H₂O

5 / 15

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

CO

Fe

CO₂

Fe₂O

6 / 15

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

physical

chemical

Both 1 & 2

none of these

7 / 15

State the reactions are exothermic or endothermic in nature: Decomposition of ferrous sulphate

endothermic reaction

exothermic reaction

Both 1 & 2

all 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 anode

H<sub>2</sub>O

Oxygen

Hydrogen

None of these

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

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

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

13 / 15

Dilute hydrochloric acid is added to granulated zinc taken in a test tube. The following observations are recorded. Designate the accurate observation:

The surface of metal becomes shiny.

The reaction mixture turns milky.

Odour of a pungent smelling gas is recorded.

A colourless and odourless gas is evolved

14 / 15

Calcium oxide reacts vigorously with water to produce slaked lime. CaO(s) + H₂O(l) → Ca(OH)₂(aq) This reaction can be classified as:

Combination reaction

Exothermic reaction

Endothermic reaction

Oxidation reaction

1 and 3

3 and 4

1, 3 and 4

1 and 2

15 / 15

Three beakers labelled as A, B and C, each containing 25 ml of water, were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in the case of beaker C, the temperature of the solution fell. Which one of the following statement(s) is (are) correct?

In beakers A and B, exothermic process has occurred.

In beakers A and B, endothermic process has occurred

In beaker C, exothermic process has occurred

In beaker C, endothermic process has occurred.

1

2

1 and 4

2 and 3

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