First, we need to calculate the molar mass of magnesium hydroxide, \(\mathrm{Mg(OH)_2}\).
- Magnesium (Mg): \(24.305 \, \text{g/mol}\)
- Oxygen (O): \(16.00 \, \text{g/mol}\)
- Hydrogen (H): \(1.008 \, \text{g/mol}\)
The molar mass of \(\mathrm{Mg(OH)_2}\) is calculated as follows:
\[
\text{Molar mass of } \mathrm{Mg(OH)_2} = 24.305 + 2 \times (16.00 + 1.008) = 58.319 \, \text{g/mol}
\]
Next, we calculate the number of moles of \(\mathrm{Mg(OH)_2}\) in 75 grams.
\[
\text{Moles of } \mathrm{Mg(OH)_2} = \frac{75 \, \text{g}}{58.319 \, \text{g/mol}} = 1.286 \, \text{mol}
\]
Magnesium sulfate (\(\mathrm{MgSO_4}\)) is used to produce magnesium hydroxide. We need to find the mass of \(\mathrm{MgSO_4}\) required to produce 1.286 moles of \(\mathrm{Mg(OH)_2}\).
The molar mass of \(\mathrm{MgSO_4}\) is:
- Magnesium (Mg): \(24.305 \, \text{g/mol}\)
- Sulfur (S): \(32.07 \, \text{g/mol}\)
- Oxygen (O): \(16.00 \, \text{g/mol} \times 4\)
\[
\text{Molar mass of } \mathrm{MgSO_4} = 24.305 + 32.07 + 4 \times 16.00 = 120.375 \, \text{g/mol}
\]
The mass of \(\mathrm{MgSO_4}\) needed is:
\[
\text{Mass of } \mathrm{MgSO_4} = 1.286 \, \text{mol} \times 120.375 \, \text{g/mol} = 154.8 \, \text{g}
\]
Sodium hydroxide (\(\mathrm{NaOH}\)) is also used in the reaction. We need to find the mass of \(\mathrm{NaOH}\) required to produce 1.286 moles of \(\mathrm{Mg(OH)_2}\).
The molar mass of \(\mathrm{NaOH}\) is:
- Sodium (Na): \(22.99 \, \text{g/mol}\)
- Oxygen (O): \(16.00 \, \text{g/mol}\)
- Hydrogen (H): \(1.008 \, \text{g/mol}\)
\[
\text{Molar mass of } \mathrm{NaOH} = 22.99 + 16.00 + 1.008 = 39.998 \, \text{g/mol}
\]
The mass of \(\mathrm{NaOH}\) needed is:
\[
\text{Mass of } \mathrm{NaOH} = 1.286 \, \text{mol} \times 39.998 \, \text{g/mol} = 51.44 \, \text{g}
\]
\[
\boxed{\text{Mass of } \mathrm{MgSO_4} = 154.8 \, \text{g}}
\]
\[
\boxed{\text{Mass of } \mathrm{NaOH} = 51.44 \, \text{g}}
\]