Chemical Effects Of Electric Current Mock Tests

24 questions available

Chemical Effects Of Electric Current Mock Test 1

Questions: 24

Sample Questions

Class 8 Science

When electric current is passed through copper sulphate solution using copper electrodes, copper gets deposited on the:

A Positive electrode (anode)

B Negative electrode (cathode)

C Both electrodes equally

D Neither electrode

Class 8 Science

Which process is used to coat a layer of zinc on iron to prevent rusting?

A Electrolysis

B Electroplating

C Crystallisation

D Fermentation

Class 8 Science

What is the purpose of electroplating a thin layer of chromium on car parts?

A To improve appearance and prevent rusting

B To increase the weight of the parts

C To make the parts more brittle

D To reduce electrical conductivity

Class 8 Science

Electroplating with chromium on iron objects is done mainly to:

A Make the iron lighter

B Prevent corrosion and give a shiny appearance

C Increase the electrical resistance of iron

D Make the iron more brittle

Class 8 Science

When zinc granules react with dilute sulphuric acid, hydrogen gas is produced. The correct observation is:

A Brown gas is evolved

B Blue colour develops

C Bubbles of gas form on zinc surface

D Zinc dissolves without any change

Class 8 Science

Which of the following is a non-conductor of electricity?

A Distilled water

B Sea water

C Acidic solution

D Basic solution

Class 8 Science

When copper sulphate solution is electrolysed using copper electrodes, what happens at the positive electrode (anode)?

A Copper deposits

B Copper dissolves

C Oxygen gas is released

D Hydrogen gas is released

Class 8 Science

Which of the following is the correct chemical formula for water?

A HO

B H₂O

C H₂O₂

D OH

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