Questions

Write down the formulae of sodium oxide.

Write down the formula of aluminium chloride.

Write down the formula of sodium sulphide.

Write down the formula of magnesium hydroxide.

Write down the names of compounds represented by the following formulae:
(i) $\mathrm{A}{\mathrm{l}}_2{\left(\mathrm{S}{\mathrm{O}}_4\right)}_3$
(ii) $\mathrm{C}\mathrm{a}\mathrm{C}{\mathrm{l}}_2$
(iii) ${\mathrm{K}}_2\mathrm{S}{\mathrm{O}}_4$
(iv) $\mathrm{K}\mathrm{N}{\mathrm{O}}_3$
(v) $\mathrm{C}\mathrm{a}\mathrm{C}{\mathrm{O}}_3$

What is meant by the term chemical formula?

How many atoms are present in a
(i) ${\mathrm{H}}_2\mathrm{S}$ molecule and
(ii) ${\mathrm{P}\mathrm{O}}_4^{3-}$ ion?