(a)[1]
Describe what you would observe when ethene gas is bubbled through aqueous bromine.
(b)[3]
Table 3.1 gives some bond energies. bond C-H: 410 kJ/mol bond C-C: 350 kJ/mol bond C=C: 610 kJ/mol bond Br-Br: 193 kJ/mol bond C-Br: 280 kJ/mol Show by calculation that the enthalpy change for the reaction between ethene and bromine, $\Delta H$, is $-107\ \text{kJ mol}^{-1}$.
(c)[3]
Complete the reaction pathway diagram in Fig. 3.2 for the reaction of ethene with bromine. Add labels for the: • reactants • product • enthalpy change of the reaction, $\Delta H$ • activation energy, $E_a$.
(d)[2]
Use a dot-and-cross diagram to show the electronic configuration in a molecule of ethene. Include only the electrons in the outer shell.