Question

Name the gas evolved when dilute HCl reacts with sodium hydrogen carbonate. How is it recognized?

Answer 1

• Dilute hydrochloric acid reacts with sodium hydrogen carbonate to evolve carbon dioxide gas. The reaction is as follows:

$NaHC{O}_3+HCl⟶NaCl+HCl+H_{2}O$

• When carbon dioxide gas is passed through lime water, the lime water turns milky due to the formation of a white precipitate of calcium carbonate.

$Ca(OH{)}_2+C{O}_2⟶CaC{O}_3+H_{2}O$