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

Baking soda (NaHCO3) on heating produces carbon dioxide (CO2), which extinguishes a burning matchstick.

But washing soda (Na2CO3.10H2O) on heating does not produce any such gas, thus, it has no effect on burning matchstick.

U are wrong. U don’t test with hydrogen gas . We pass the gas through limewater which turns milky due to carbon dioxide.