Question

What is the chemical formula of sodium carbonate? [2 marks]

Answer 1

The constituent ions present in sodium carbonate are ${\text{Na}}^{+}$ and ${\text{CO}}_3^{2-}$. [1 mark]

Symbol	Na	CO3
Charge	+1	-2

[1 Mark]

To balance the charges, we cross multiply the valencies and get the chemical formula of sodium carbonate as Na₂CO₃
[1 mark]