Respuesta :

Answer: The mass of iron (III) oxide needed to react is 67.4 g

Explanation:

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

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]      .....(1)

Given mass of carbon = 19.0 g

Molar mass of carbon = 12 g/mol

Putting values in equation 1, we get:

[tex]\text{Moles of carbon}=\frac{19.0g}{12g/mol}=1.58mol[/tex]

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

[tex]2Fe_2O_3+3C\rightarrow 3CO_2+4Fe[/tex]

By Stoichiometry of the reaction:

3 moles of carbon reacts with 2 moles of iron (III) oxide

So, 1.58 moles of carbon will react with = [tex]\frac{2}{3}\times 1.58=0.422mol[/tex] of iron (III) oxide

Now, calculating the mass of iron (III) oxide by using equation 1, we get:

Molar mass of iron (III) oxide = 159.70 g/mol

Moles of iron (III) oxide = 0.422 moles

Putting values in equation 1, we get:

[tex]0.422mol=\frac{\text{Mass of iron (III) oxide}}{159.70g/mol}\\\\\text{Mass of iron (III) oxide}=(0.422mol\times 159.70g/mol)=67.4g[/tex]

Hence, the mass of iron (III) oxide needed to react is 67.4 g