Lawrie Ryan and Roger Norris Solutions for Chapter: Group 17, Exercise 1: BEFORE YOU START

Write down the electronic configuration of a bromine atom.

The oxidation number of chlorine can vary. Give its oxidation number in $\mathrm{NaCl}$.

The oxidation number of chlorine can vary. Give its oxidation number in $\mathrm{NaClO}$.

Explain which element is oxidised and which is reduced in this reaction:

$2\mathrm{Fe}\left(\mathrm{s}\right) + 3{\mathrm{Cl}}_2\left(\mathrm{g}\right) \to 2{\mathrm{FeCl}}_3 \left(\mathrm{s}\right)$

Draw a dot-and-cross diagram to show the covalent bonding in a chlorine molecule, ${\mathrm{Cl}}_2$. Only include outer shell electrons.

Discuss with a partner what we mean by 'bond energy'.

State the unit that bond energies are expressed in.