$(i)$ What is meant by the term hydrated salt?
$(ii)$ Give two examples of hydrated salts that are white in color and state their chemical formulas.

$A$ sulphate salt of a Group $2$ element of the Periodic Table is a white,soft substance,which can be moulded into different shapes by making its dough. When this compound is left in the open for some time,it becomes a hard solid mass and cannot be used for moulding purposes. Identify the sulphate salt and explain why it shows such behavior. Provide the chemical reaction involved.

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

Salt $A$,commonly used in bakery products,on heating gets converted into another salt $B$,which itself is used for the removal of hardness of water,and a gas $C$ is evolved. The gas $C$,when passed through lime water,turns it milky. Identify $A$,$B$,and $C$.

Write an equation to show the reaction between Plaster of Paris and water.

Give two important uses of washing soda and baking soda.