PPSC MCQs

Galvanization covers iron or steel with zinc.
The coating blocks moisture and can protect sacrificially.

The reaction produces carbon dioxide gas.
Gas bubbles become trapped and expand during heating.

Paint forms a protective barrier.
This slows the electrochemical reactions that cause rust.

Washing soda is hydrated sodium carbonate.
It is used for cleaning and softening water.

Corrosion involves chemical or electrochemical reactions.
Rusting is a common example involving iron.

Bleaching powder releases chlorine-containing disinfecting agents.
It is used in water treatment and bleaching.

Acids donate protons in chemical reactions.
In water, they increase hydrogen-ion concentration.

Chlorine in controlled amounts disinfects water.
It reduces disease-causing bacteria and viruses.

Bases accept protons according to Brønsted-Lowry theory.
Many aqueous bases produce hydroxide ions.

pH values below 7 indicate acidity.
A pH of 3 is distinctly acidic.

pH values above 7 indicate basicity.
A pH of 10 is alkaline.

Litmus changes color depending on acidity or basicity.
Red litmus turns blue in bases, while blue litmus turns red in acids.