Question

(a) What happens when dilute hydrochloric acid is added to sodium carbonate? Write a balanced chemical equation of the reaction involved.
(b) Which gas is liberated when dilute hydrochloric acid reacts with sodium carbonate? How will you test for the presence of this gas?

Answer 1

a) dil.HcL+Na2Co3-------NaCl + H2O+Co2

b) carbon dioxide gas is liberated

Answer 2

Washing Soda is Basic in Nature

Explanation:

• Sodium carbonate commonly known as washing soda is basic. So it can react with dil. HCl. The reaction gives table salt (NaCl), carbon dioxide and water.

$Na-2CO_3+2 HCl ---> 2 NaCl +CO_2+H_2O$

When you mix sod.carbonate and HCl, two molecules of HCl give two $H^+$ ions which react with $Na_2CO_3$ and give carbonic acid ($H_2CO^-^3$) which is quite unstable and splits into $CO_2\ and\ H_2O$. Two $Na_+$ ion react with two $Cl^-$ ion to give two NaCl molecules.

b.) Sodium Hydrogen Carbonate and dil Hydrochloric Acid reacts to give $CO_2$ (Carbon dioxide)

• But $CO_2$ (Carbon dioxide) shows its presence when Lime Water turns milky or we see $CaCo_3$ (Calcium Carbonate) formation.

• When an excess of $CO_2$ (Carbon dioxide) is passed through lime water, the solution becomes clear.