How would you distinguish between baking powder and washing soda by heating ?

Explanation

The chemical formula of baking powder is sodium hydrogencarbonate `(NaHCO_(3))` whereas, that of washing soda is sodium carbonate `(Na_(2)CO_(3).10H_(2)O)`. Sodium hydrogencarbonate on heating gives `CO_(2)` gas which will turn lime water milky whereas no such gas is obtained from sodium carbonate. `2NaHCO_(3) - "Heat" rarr Na_(2)CO_(3) + H_(2)O + CO_(2)`
`Na_(2)CO_(3).10H_(2)O rarr "Heat" rarr Na_(2)CO_(3) + 10H_(2)O`