Question

When iron(III) oxide reacts with hydrochloric acid, iron(III) chloride and water are formed. How many grams of iron(III) chloride are formed from 10.0 g of iron(III) oxide and 10.0 g of hydrochloric acid

Answer 1

Answer: The mass of iron (III) chloride produced is 14.81 grams

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$     .....(1)

• For iron(III) oxide:

Given mass of iron(III) oxide = 10.0 g

Molar mass of iron(III) oxide = 159.7 g/mol

Putting values in equation 1, we get:

$\text{Moles of iron(III) oxide}=\frac{10.0g}{159.7g/mol}=0.0626mol$

• For hydrochloric acid:

Given mass of hydrochloric acid = 10.0 g

Molar mass of hydrochloric acid = 36.5 g/mol

Putting values in equation 1, we get:

$\text{Moles of hydrochloric acid}=\frac{10.0g}{36.5g/mol}=0.274mol$

The chemical equation for the reaction of iron (III) oxide and hydrochloric acid follows:

$Fe_2O_3+6HCl\rightarrow 2FeCl_3+3H_2O$

By Stoichiometry of the reaction:

6 moles of hydrochloric acid reacts with 1 mole of iron (III) oxide

So, 0.274 moles of hydrochloric acid will react with = $\frac{1}{6}\times 0.274=0.0456mol$ of iron (III) oxide

As, given amount of iron (III) oxide is more than the required amount. So, it is considered as an excess reagent.

Thus, hydrochloric acid is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

6 moles of hydrochloric acid produces 2 moles of iron (III) chloride

So, 0.274 moles of hydrochloric acid will produce = $\frac{2}{6}\times 0.274=0.0913moles$ of iron (III) chloride

Now, calculating the mass of iron (III) chloride from equation 1, we get:

Molar mass of iron (III) chloride = 162.2 g/mol

Moles of iron (III) chloride = 0.0913 moles

Putting values in equation 1, we get:

$0.0913mol=\frac{\text{Mass of iron (III) chloride}}{162.2g/mol}\\\\\text{Mass of iron (III) chloride}=(0.0913mol\times 162.2g/mol)=14.81g$

Hence, the mass of iron (III) chloride produced is 14.81 grams