Question

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

Answer 1

• Baking soda is sodium hydrogen carbonate (NaHCO₃). Upon heating, it will evolve CO₂ gas which upon passing through lime water, will make it milky.
  `2"NaHCO"_3 overset("heat")(-> )"Na"_2"CO"_3 + "H"_2"O" + "CO"_2`
• Washing soda is sodium carbonate decahydrate (Na₂CO₃.10H₂O). Upon heating, it will not evolve any gas.
  `"Na"_2"CO"_3. 10"H"_2"O" overset("heat")(->) "Na"_2"CO"_3 + 10"H"_2"O"`