Question

Explain the following method with example.  

Double decomposition (precipitation)

Answer 1

Decomposition of hydrogen by acids.

(1) \[\ce{\underset{bicarbonate}{\underset{Sodium}{NaHCO3}}+ HCl -> \underset{salt}{NaCl}+H2O + CO2\uparrow}\]

(2) \[\ce{\underset{bicarbonate}{\underset{Calcium}{Ca(HCO3)}}+ 2HNO3 -> \underset{salt}{Ca(NO3)2}+ 2H2O + 2CO2\uparrow}\]

Decomposition of carbonates by acids.

(1) \[\ce{\underset{carbonate}{\underset{Copper}{CuCO3}}+ 2HCl -> \underset{salt}{CuCl2}+ H2O + CO2\uparrow}\]

(2) \[\ce{\underset{carbonate}{\underset{Magnesium}{MgCO3}}+H2SO4 -> \underset{salt}{MgSO4}+H2O + CO2\uparrow}\]