Question

What happens when solid sodium hydrogen carbonate is heated?

Answer 1

When NaHCO₃ is heated , it gives out a colourless , odourless gas , which turns lime water milky and has no response to Potassium Permanganate . This gas is Carbon Dioxode  and water , which turns blue cobalt chloride paper pink.
 
                Δ
NaHCO₃------>Na₂O + H₂O + CO₂