page 03 5. A disproportionation reaction is a redox reaction in which an element in a single substance is both oxidised and reduced. In which of the following does a halogen undergo disproportionation? A Cl2  +  2KI  ↓  2KCl  +  I2 B IO3 −  +  5I−  +  6H+  ↓  3I2  +  3H2O C I2  +  6H2O  +  5Cl2  ↓  2HIO3  +  10HCl D Cl2  +  2NaOH  ↓  NaCl  +  NaClO  +  H2O 6. Which of the following is true for a neutral solution at 325 K? A pH = 7.00 B Kw = 1.01 × 10−14 C [H3O+] = [OH−] D [H3O+] = 1.00 × 10−7 7. 2SO2(g)  +  O2(g)  Ý  2SO3(g) ΔH = −196 kJ mol−1 Which line in the table is correct for the concentration of SO3(g) at equilibrium and the equilibrium constant, K, when the pressure of the equilibrium mixture is increased at constant temperature? [SO3(g)] at equilibrium Equilibrium constant, K A increase no change B increase increase C no change increase D no change no change 8. The standard enthalpy of formation of sodium chloride is represented by: A Na+(g)  +  Cl−(g)  ↓  Na+Cl−(g) B Na+(g)  +  Cl−(g)  ↓  Na+Cl−(s) C Na(s)  +  Cl(g)  ↓  Na+Cl−(s) D Na(s)  +  1 2Cl2(g)  ↓  Na+Cl−(s) [Turn over