This question is about elements and compounds - AQA - GCSE Chemistry Combined Science - Question 7 - 2022 - Paper 1

The balanced equation is:

$4 Na + TiCl_4 → 4 NaCl + Ti$

The half-equation showing that sodium is oxidised is:

$Na → Na^+ + e^-$

First, determine the number of moles of aluminum:

$ext{moles of Al} = \frac{108 ext{ g}}{27 ext{ g/mol}} = 4 ext{ moles}$

According to the reaction equation:

$2 ext{Al} + 3 ext{CuCl}_2 → 3 ext{Cu} + 2 ext{AlCl}_3$

4 moles of Al will produce 6 moles of Cu. Next, calculate the moles of CuCl₂:

$ext{moles of CuCl}_2 = \frac{1.21 ext{ kg}}{134.5 ext{ g/mol}} = 8.996 ext{ moles}$

Since Al is the limiting reactant, the maximum mass of copper produced is:

$6 ext{ moles Cu} \times 63.5 ext{ g/mol} = 381 ext{ g}$

Sodium metal conducts electricity due to the presence of delocalised electrons. These free electrons can move throughout the metal lattice, allowing an electrical charge to flow when a voltage is applied.

Sodium chloride can conduct electricity when it is melted or dissolved in water, as it dissociates into its ionic components (Na⁺ and Cl⁻ ions). These ions are free to move and carry an electric charge, enabling conductivity.