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

Explanation

Washing soda is a hydrated salt .Its molecular formula is `Na_(2)CO_(3)*10H_(2)O` . Baking powder `(NaHCO_(3))` does not contain water of crystallisation .
On heating , washing soda loses its water of crystallisation .This water can be seen as droplets in the upper part of the test tube .
`Na_(2)CO_(3)*10H_(2)Ooverset("heat")toNa_(2)CO_(3)+10H_(2)O`
On heating , baking soda `(NaHCO_(3))` decomposes to give `CO_(2)` gas . `CO_(2)` gas when passed through limewater , turn it milky .