Answer to Question #198166 in Chemistry for Jordan Weissert

Question

In a very violent reaction called the thermite reaction, aluminum metal reacts with iron (III) oxide to form iron metal and aluminum oxide.

Fe₂O₃ + AI → Fe + Al₂O₃

What mass of aluminum will react 150 g of iron (III) oxide?

Answer 1

Solution:

Balanced chemical equation:

Fe₂O₃ + 2AI → 2Fe + Al₂O₃

The molar mass of Fe₂O₃ is 159.69 g/mol.

Therefore,

(150 g Fe₂O₃) × (1 mol Fe₂O₃ / 159.69 g Fe₂O₃) = 0.9393 mol Fe₂O₃

According to the equation above: n(Fe₂O₃) = n(Al)/2

n(Al) = 2 × n(Fe₂O₃) = 2 × 0.9393 mol = 1.8786 mol

The molar mass of Al is 26.98 g/mol.

Therefore,

(1.8786 mol Al) × (26.98 g Al / 1 mol Al) = 50.68 g Al

Answer: 50.68 grams of aluminum (Al) will react.

OR (short form solution)

According to the equation above:

(150 g Fe₂O₃)×(1 mol Fe₂O₃/159.69 g Fe₂O₃)×(2 mol Al/1 mol Fe₂O₃)×(26.98 g Al/1 mol Al) = 50.68 g Al