On what basis are acids classified as strong and weak acids?

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

The physiological reactions occurring in the human body take place in the range of $......\,pH.$

If the $pH$ of the aqueous solutions $A, B, C$ and $D$ are $1.9, 2.5, 2.1$ and $3.0$ respectively,then what will be the order of acidity?

$Na_{2}CO_{3} \cdot 10H_{2}O$ and $Na_{2}CO_{3}$ are two chemical compounds. Write their chemical names. Explain the significance of $10H_{2}O$ and mention the term used for water molecules attached to a salt.

What is the concentration of $[OH^-]$ in distilled water at $298 \; K$?