Question

Match the following reactions with the changes observed during each of them.

• A. Change in colour
• B. Gas is evolved
• C. Formation of ppt

Answer 1

Copper sulphate solution is blue in colour. When powdered zinc is added to it, the solution turns colourless due to the formation of zinc sulphate solution.
Here, the reaction is:
${\text{CuSO}}_4\text{(aq)}+\text{Zn(s)}\to {\text{ZnSO}}_4\text{(aq)}+\text{Cu(s)}$

Iron reacts with hydrochloric acid to form ferrous chloride and releases hydrogen gas.
$\text{Fe (s)}+\text{2HCl (aq)}\to {\text{FeCl}}_2\text{(aq)}+{\text{H}}_2\text{(g)}$

The reaction between silver nitrate and sodium chloride is a precipitation reaction in which an insoluble precipitate of silver chloride is formed.
${\text{AgNO}}_3\text{(aq)}+\text{NaCl (aq)}\to {\text{NaNO}}_3\text{(aq)}+\text{AgCl(s)}$