Question

How can you name chemical compounds from their formula in the following cases? Give examples in support of your answer.

(iii) If a compound contains three elements (tertiary compound), one of which is Oxygen.

Answer 1

• If a compound contains three elements (tertiary compound), one of which is oxygen then this oxygen must be combined with other metals or non-metals to form an ion such as Chromate ion${\left({\mathrm{Cr}}_2{\mathrm{O}}_7\right)}^{-2}$, sulfate ion${\left({\mathrm{SO}}_4\right)}^{-2}$etc.
• While writing the formula of an ionic compound, the metal is written on the left-hand side, while the non-metallic ion is written on the right-hand side.
  The name of the metal and non-metallic ion remains the same.
• Example: The compound formed between potassium(K) and chromate ion ${\left({\mathrm{Cr}}_2{\mathrm{O}}_7\right)}^{-2}$is$\left({\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\right)$, known as potassium dichromate.