Statements (ii), (iii) and (v) are correct whereas statements (i) and (iv) are incorrect. (i) Thermal decomposition of HI on gold surface is zero order reaction. (ii) Thermal decomposition of N2O5(g) at constant volume is first order reaction. (iii) Hydrogenation of ethene is first order reaction. (iv) Decomposition of NH3 on a hot platinum surface is a zero order reaction. (v) Thermal decomposition of SO2Cl2(g) at constant volume is a first order reaction.