(i) CaF2+ H2SO4 → CaSO4+ 2HF

(ii) 2HI + H2SO4 → I2 + SO2+ 2H2O

(iii) Cu + 2H2SO4 → CuSO4 + SO2 + 2H2O

(iv) NaCl + H2SO4 → NaHSO4 + HCl

Correct Answers: 

(ii) 2HI + H2SO4 → I2 + SO2+ 2H2O

(iii) Cu + 2H2SO4 → CuSO4 + SO2 + 2H2O

Explanation: Concentrated Sulphuric acid is used as an oxidising reagent in the following reactions,

2HI + H2SO4 → I2 + SO2+ 2H2O & Cu + 2H2SO4 → CuSO4 + SO2 + 2H2O