(a)[3]
Complete the dot-and-cross diagram below to show the bonding in ammonium chloride. Show all the outer-shell electrons for each of the six atoms. Three electrons have already been drawn. Use this code for the electrons: electrons from chlorine, electrons from hydrogen, electrons from nitrogen.
(b(i))[1]
Suggest why concentrated $\text{H}_2\text{SO}_4$, the standard drying agent for gases, is not used to dry ammonia.
(b(ii))[1]
Write an equation for the reaction of $\text{CaO}$ with $\text{H}_2\text{O}$.
(b(iii))[1]
Suggest why $\text{CaO}$ is used instead of $\text{MgO}$ to dry ammonia.
(c(i))[2]
Write an equation showing the thermal decomposition of calcium nitrate, $\text{Ca(NO}_3)_2$.
(c(ii))[2]
State and explain how the thermal stabilities of the nitrates change down Group II.