Common salt, besides being used in the kitchen, can also be used as the raw material for making:
$(i)$ Washing soda
$(ii)$ Bleaching powder
$(iii)$ Baking soda
$(iv)$ Slaked lime

The compound which is used for removing permanent hardness of water is:

In the following schematic diagram for the preparation of hydrogen gas as shown in the Figure,what would happen if the following changes are made?
$(a)$ In place of zinc granules,the same amount of zinc dust is taken in the test tube.
$(b)$ Instead of dilute sulphuric acid,dilute hydrochloric acid is taken.
$(c)$ In place of zinc,copper turnings are taken.
$(d)$ Sodium hydroxide is taken in place of dilute sulphuric acid and the tube is heated.

$A$ compound $X$ is a constituent of baking powder. It is used as an antacid. When $X$ is heated, it releases a gas $Y$ which, when passed through lime water, turns it milky, and a salt $Z$ is formed, which is the main constituent of washing powder. Identify $X, Y$, and $Z$. Write balanced chemical equations for the reactions involved.

What is correct for an acidic aqueous solution?

$(a)$ $A$ salt is produced by the reaction between an acid and a base. Identify the acid and the base from which the following salts have been formed:
$(i)$ $Na_{2}SO_{4}$
$(ii)$ $NH_{4}Cl$
$(iii)$ $KNO_{3}$
$(iv)$ $NaCl$