Calculate the percentage of phosphorus in the fertilizer superphosphate Ca(H₂PO₄)₂. (correct to 1 dp)

[H = 1 ; O = 16 ; P = 31 ; Ca = 40]

Calculate the percentage of platinum in ammonium chloroplatinate (NH₄)₂ PtCl₆

(Give your answer correct to the nearest whole number.

[N = 14, H = 1, Cl = 35.5, Pt = 195]

Calculate the percentage of sodium in sodium aluminium fluoride (Na₃AlF₆) correct to the nearest whole number.

[F = 19 ; Na = 23 ; Al = 27]

Determine the percentage of oxygen in ammonium nitrate

[O = 16]