What is the $pH$ value of a $1 \times 10^{-5} \; M$ aqueous solution of $NaOH$?

During the preparation of hydrogen chloride gas on a humid day,the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to

How is an aqueous solution with $pH$ $12$ compared to an aqueous solution with $pH$ $9$?

In one of the industrial processes used for the manufacture of sodium hydroxide,a gas $X$ is formed as a by-product. The gas $X$ reacts with lime water to give a compound $Y$,which is used as a bleaching agent in the chemical industry. Identify $X$ and $Y$ and provide the chemical equations for the reactions involved.

Write the balanced chemical equations for the following reactions:
$(a)$ Chlorine is passed over dry slaked lime.
$(b)$ Sodium bicarbonate reacts with dilute hydrochloric acid.
$(c)$ Sodium bicarbonate is heated.

Which of the following is a strong acid?