(i) Covalent bonds between: S and O «within the sulfate ion» ✔

Ionic bonds between: $\ce{Ga^3+}$ and $\ce{SO4^2-}$ ✔

(ii) in a covalent bond the valence electrons are shared between the atoms, whereas in an ionic bond they are transferred from one atom to another ✔

(iii) $\ce{2Ga(OH)3(s) + 3H2SO4(aq) -> Ga2(SO4)3(aq) + 6H2O(l)}$

correct formulas of the products ✔

correctly balanced equation ✔

(iv) $M(\ce{Ga(OH)3}) = 69.72 + 3(16.00 + 1.01) = 120.75$

$n(\ce{H2SO4}) = \dfrac{3}{2} \times 0.0500 = 0.0750$

$V = \dfrac{0.0750}{1.50} = 0.0500$ «$\mathrm{dm^3}$» / 50.0 «$\mathrm{cm^3}$

(v) yes AND gallium is in the same group as aluminium, whose hydroxide and oxide are amphoteric «$\ce{Ga(OH)3}$ reacts with both acids and alkalis» ✔

(vi) place a piece of gallium in aqueous nickel(II) sulfate «or a piece of nickel in aqueous gallium(III) sulfate» ✔

a deposit of nickel «and fading of the green colour» shows that gallium is the more reactive metal / no change when nickel is placed in gallium(III) sulfate shows that nickel is the less reactive metal ✔

(i) [2] one mark for each pair of particles. (ii) [1] sharing contrasted with transfer; accept 'gain and loss' for transfer. (iii) [2] M1 correct formulas of gallium(III) sulfate and water; M2 balanced. (iv) [3] M1 amount of gallium(III) hydroxide; M2 amount of acid from the 2:3 ratio; M3 volume; award [3] for a correct final answer; ECF from M1 and M2. (v) [1] the prediction must be justified by the position of gallium below aluminium in group 13. (vi) [2] M1 a valid displacement experiment; M2 how the observation is interpreted.