Q8 of 29 Page 73

Answer the following questions.

Explain what is meant by electrolysis of water. Write the electrode reactions and explain them.

Electrolysis of water: It is defined as the process of decomposition of water into hydrogen and oxygen gas by the passage of electricity through its aqueous solution (water).



i. At the cathode (negative electrode), reduction takes place and evolves hydrogen gas:


Reduction reaction: 2H+ + 2e-→ H2


ii. At the anode (positive electrode), osidation takes place and evolves oxygen gas:


Oxidation reaction: 2H2O → O2 + 4H+ + 4e-


iii. Overall cell reaction: 2H2O → 2H2 + O2


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8

Answer the following questions.

Classify the acids according to their basicity and give one example of each type.

 8

Answer the following questions.

What is meant by neutralization? Give two examples from everyday life of the neutralization reaction.

 9

Give reason for the following.

A. Hydronium ions are always in the form H3O+


B. Buttermilk spoils if kept in a copper or brass container.

 10

Write the chemical equations for the following activities.

A. NaOH solution was added to HCl solution.


B. Zinc dust was added to dilute


C. Dilute nitric acid was added to calcium oxide.


D. Carbon dioxide gas was passed through KOH solution.


E. Dilute HCl was poured on baking soda.