What is the unit of molar mass?

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

Write true or false for the following statement:
Acids that give rise to more $H^+$ ions are said to be strong acids,and acids that give less $H^+$ ions are said to be weak acids.

Name the acid and base from which the following salts have been formed:
$(i)$ Sodium acetate.
$(ii)$ Ammonium chloride.

Give the chemical name and formula of:
$(i)$ Soda ash
$(ii)$ Blue vitriol
$(iii)$ Baking soda

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