Question

(a) The recovery of silver from silver nitrate solution involves displacement by copper metal. Write the equation of the reaction that takes place. Give the states of all the substances.
(b) Under what soil conditions do you think a farmer would treat the soil in his fields with quicklime? Why?
(c) Name one sodium compound which is used for softening hard water and another which is used in fire extinguishers.

Answer 1

(a) Silver can be recovered from the silver nitrate solution by the displacement by copper metal as follows:
$2{\mathrm{AgNO}}_3\left(\mathrm{aq}\right)+\mathrm{Cu}\left(\mathrm{s}\right)\to \mathrm{Cu}\left({\mathrm{NO}}_3{)}_2\right(\mathrm{aq})+2\mathrm{Ag}(\mathrm{s})$

(b) If the soil is acidic and improper for cultivation, then to increase the basicity of soil, the farmer would treat the soil with quick lime.

(c) Sodium carbonate (${\mathrm{Na}}_2{\mathrm{CO}}_3.10{\mathrm{H}}_2\mathrm{O}$) is used for softening of hard water.
Sodium bicarbonate (${\mathrm{NaHCO}}_3$) is used in the fire extinguisher.