A white powdery substance having strong smell of chlorine is used for disinfecting drinking water supply at waterworks. Identify the substance. Give its chemical name and write the chemical reaction for its preparation.

A compound X which is prepared from gypsum has the property of hardening when mixed with a proper quantity of water.

(a) Identify the compound X

(b) Write the chemical equation for its preparation

(c) For what purpose is it used in hospitals?

Consider the following salts:

Na₂CO₃, NaCI, NH₄CI, CH₃COONa, K₂SO₄, (NH₄)zSO₄

Which of these salts will give:

(a) acidic solutions?

(b) neutralsolutions?

(c) basic solutions (or alkaline solutions)?

A salt X when dissolved in distilled water gives a clear solution which turns red litmus blue. Explain the phenomenon.

A person found that the cake prepared by him is hard and small in size. Which ingredient has he forgotten to add that would have caused the cake to rise and become light? Explain your answer.