Question

Calculate the percent composition by mass of each element in magnesium sulfate.

Answer 1

`\begin{gathered} \%Mg=20.19\% \\ \%S=26.64\% \\ \%O=53.17\% \end{gathered}`

Explanations

The chemical compound for magnesium sulfate is given as MgSO₄.

Given the following known parameters:

Molar mass of magnesium = 24.305 g/mol

Molar mass of sulfur = 32.065 g/mol

Molar mass of oxygen = 16.00g/mol

The molar mass of magnesium sulfate is calculated as shown below:

`\begin{gathered} \text{Molar mass of MgSO}_4=24.305+32.065+4(16.00) \\ \text{Molar mass of MgSO}_4=120.37g\text{/mol} \end{gathered}`

Determine the percent composition by mass of Magnesium

`\begin{gathered} \%Mg=\frac{Molar\text{ mass of Mg}}{120.37}*100 \\ \%Mg=(24.305)/(120.37)*100 \\ \%Mg=0.2019*100 \\ \%Mg=20.19\% \end{gathered}`

For the percent composition by mass of sulfur:

`\begin{gathered} \%S=\frac{Molar\text{ mass of S}}{120.37}*100 \\ \%S=(32.065)/(120.37)*0 \\ \%S=0.2664*100 \\ \%S=26.64\% \end{gathered}`

For the percent composition by mass of oxygen

`\begin{gathered} \%O=\frac{Molar\text{ mass of O}}{120.37}*100 \\ \%O=(64.0)/(120.37)*100 \\ \%O=0.5317*100 \\ \%O=53.17\% \end{gathered}`