Categorise in to reversible and irreversible process. (i) Water fall, (ii) rusting of iron, (iii) electrolysis, (iv) diffusion of gas. (v) melting of ice, (vi) dissolving NaCl in water, (vii) flow of heat from hot body to cool body

Which of following are open, close or nearly isolated systéms? i) Human beings, ii). the earth. iii) can of tomato soup iv) ice cube tray filled with water v) coffee in'a thermoflask vi) helium-filled balloon. .

Select correct statement. (i) Mixture of NH_4Cl and NaNO_2 on heating gives N_2 gas . ( ii) CFC is used as refrigerating fluid and as propellant in aerosols ( iii) Phosgene is formed when P_4 reacts with NaOH (iv) Phosgene dissolves in water forming P_2O_5