what is the percent by mass of magnesium sulfate in mgso₄·7h₂o? use %element = $\frac{total mass of element…

Explanation:

Step1: Calculate molar mass of $MgSO_4$

The molar mass of $Mg$ is approximately $24.31\ g/mol$, $S$ is approximately $32.07\ g/mol$, and $O$ is approximately $16.00\ g/mol$. For $MgSO_4$, $M_{MgSO_4}=24.31 + 32.07+4\times16.00=24.31 + 32.07 + 64.00 = 120.38\ g/mol$.

Step2: Calculate molar mass of $MgSO_4\cdot7H_2O$

The molar mass of $H_2O$ is $2\times1.01+16.00 = 18.02\ g/mol$. For $MgSO_4\cdot7H_2O$, $M_{MgSO_4\cdot7H_2O}=120.38+7\times18.02=120.38 + 126.14=246.52\ g/mol$.

Step3: Calculate mass - percent of $MgSO_4$

Using the formula $%\text{Element}=\frac{\text{total mass of element in compound}}{\text{molar mass of compound}}\times100$, for $MgSO_4$ in $MgSO_4\cdot7H_2O$, $%\text{MgSO}_4=\frac{120.38}{246.52}\times100\approx48.83%$.

Answer:

B. 48.83%