Find the total number of atoms present in one $SO_{4}^{2-}$ ion.

Calculate the number of moles in $60 \text{ g}$ of carbon. (in $\text{ moles}$)

Identify the cations and anions present (if any) in the following compounds:
$(a)$ $CH_3COONa$
$(b)$ $NaCl$
$(c)$ $H_2$
$(d)$ $NH_4NO_3$

As per the law of definite proportion,carbon and oxygen combine in the ratio of $3:8$. Compute the mass of oxygen gas that would be required to react completely with $15\,g$ of carbon.

State whether the following statement is true or false:
Mass of two moles of atoms or molecules is called molar mass.

Write the molecular formulae for the following compounds:
$(a)$ Copper $(II)$ bromide
$(b)$ Aluminium $(III)$ nitrate
$(c)$ Calcium $(II)$ phosphate
$(d)$ Iron $(III)$ sulphide
$(e)$ Mercury $(II)$ chloride
$(f)$ Magnesium $(II)$ acetate