Titanium is a transition metal - AQA - GCSE Chemistry - Question 8 - 2018 - Paper 1

Water reacts vigorously with sodium, producing hydrogen gas, which is explosive and can cause fires.

The reaction is carried out in argon to prevent the formation of sodium hydroxide, which would occur if sodium reacted with moisture or oxygen in the air.

Titanium chloride is predominantly ionic, and ionic compounds typically have high melting points due to strong electrostatic forces between ions. Therefore, it may be expected to be a solid at room temperature.

This is an oxidation reaction because sodium atoms lose electrons to form sodium ions, which is a characteristic of oxidation.

Na → Na⁺ + e⁻

To calculate the moles of TiCl₄, we use the formula:

ext{Moles} = rac{ ext{mass}}{ ext{molar mass}}

The molar mass of TiCl₄ is 190 g/mol. For 40 kg (40000 g) of TiCl₄, the moles would be:

ext{Moles of TiCl₄} = rac{40000 g}{190 g/mol} = 210.53 ext{ mol}

For 20 kg of sodium, the moles would be:

ext{Moles of Na} = rac{20000 g}{23 g/mol} ext{ (approx. 870 mol)}

Hence, TiCl₄ is the limiting reactant as there aren’t enough moles of TiCl₄ to react with the amount of sodium provided.

The actual mass of titanium produced can be calculated using the percentage yield:

ext{Actual mass} = rac{ ext{Percentage Yield}}{100} imes ext{Theoretical Mass}

Substituting the values:

ext{Actual mass} = rac{92.3}{100} imes 13.5 ext{ kg} = 12.46 ext{ kg}