What is the $pH$ value for a neutral aqueous solution?

Dry hydrogen chloride gas does not turn blue litmus red whereas hydrochloric acid does. Give one reason.

Write true or false for the following statement:
The universal indicator shows the same colour at different concentrations of hydrogen ions in a solution.

Identify the correct representation of the reaction occurring during the chlor-alkali process.

What effect does an increase in the concentration of $H^{+}(aq)$ in a solution have on the $pH$ of the solution?

$(a)$ Study the following chemical equation:
$CaSO_4 \cdot 2H_2O \xrightarrow{373K} CaSO_4 \cdot \frac{1}{2}H_2O + \frac{3}{2}H_2O$
Name the reactant and the product. State one use of the product.