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

The balanced equation is: $4 Na + TiCl₄ → 4 NaCl + Ti$

The half-equation showing the oxidation of sodium is: $Na → Na^+ + e^-$

First, calculate the moles of aluminum and copper chloride:

$\text{Moles of Al} = \frac{108 \ g}{27 \ g/mol} = 4 \ mol$ $\text{Moles of CuCl}_2 = \frac{1210 \ g}{134.5 \ g/mol} = 9 \ mol$

According to the reaction: $2 \text{Al} + 3 \text{CuCl}_2 \rightarrow 3 \text{Cu} + 2 \text{AlCl}_3$

From the equation, 4 moles of Al produces 6 moles of Cu, hence: $4 \times \frac{3}{2} = 6 \ ext{moles of Cu}$

Since 4 moles of Al will react with 6 moles of CuCl₂, which exceeds the available 9 moles of CuCl₂, aluminum is the limiting reactant.

The mass of copper produced can be calculated as: $\text{Mass of Cu} = 6 \ mol \times 63.5 \ g/mol = 381 \ g$

Sodium metal conducts electricity due to the presence of delocalised electrons. These free electrons allow the conduction of electric current by moving freely through the metal lattice.

Sodium chloride can conduct electricity in its molten state or when dissolved in water. This occurs because the ionic bonds break, allowing the ions (Na⁺ and Cl⁻) to move freely. These ions are able to carry an electric charge, facilitating conductivity.