Question

In the synthesis of iron (iii) oxide, how many grams of iron were consumed if the product of the reaction is 1.80g of iron (iii) oxide?

Answer 1

0.0225 moles

Step-by-step explanation:

iron (iii) oxide has a chemical formula of Fe2O3.

This means that for every mole of iron 3 oxide formed, 2 moles of Fe and 3 moles of oxygen is needed.

By stoichiometry we know that moles=mass ÷ Mr

Ar of Fe is approximately 56

Ar of O is approximately 16

Mr of Fe2O3 is 56(2) + 3(16) = 160.

moles of fe2o3= 1.80÷160 = 0.01125 mol

Since 2 moles of Fe is needed for the synthesis,

moles of Fe needed is 0.01125 x 2 =0.0225 moles