Write the chemical names of two salts belonging to the sodium family.

Tap water conducts electricity,whereas distilled water does not. Why?

$(a)$ What is a universal indicator?
$(b)$ Write the chemical equation involved in the preparation of sodium hydroxide. Name the process.

An aqueous solution turns red litmus solution blue. Excess addition of which of the following solution would reverse the change?

What are strong and weak acids? In the following list of acids,separate strong acids from weak acids: Hydrochloric acid,citric acid,acetic acid,nitric acid,formic acid,sulphuric acid.

What range of $pH$ is considered perfect for a fertile land?