Question

Write the chemical formula of the following compound in a step-by-step manner –

Sodium zincate

Answer 1

Write the formula of

Sodium zincate	Symbol	Valency
Sodium	\[\ce{Na}\]	\[\ce{1^{+}}\]
Zincate	\[\ce{ZnO2}\]	\[\ce{2^{-}}\]

Step I – Write each symbol with its valency.
Positive ion is written first
\[\ce{Na}^{1+}\]  \[\ce{[ZnO2]}^{2-}\]
Step II – Interchange the valencies ignoring (+) and (−) signs.

The Formula is \[\ce{Na2ZnO2}\]