Sure! Let's solve this problem step by step.
1. Find the molar mass of magnesium chloride (MgCl₂):
- Magnesium (Mg) has an atomic mass of approximately 24.305 g/mol.
- Chlorine (Cl) has an atomic mass of approximately 35.453 g/mol.
- Since there are two chlorine atoms in magnesium chloride, we calculate the molar mass as follows:
[tex]\[
\text{Molar mass of MgCl}_2 = 24.305 \, \text{g/mol (Mg)} + 2 \times 35.453 \, \text{g/mol (Cl)} = 95.211 \, \text{g/mol}
\][/tex]
2. Convert the mass of magnesium chloride to moles:
- We are given that the mass of MgCl₂ is 0.0750 grams.
- To find the number of moles, we use the formula:
[tex]\[
\text{Moles of MgCl}_2 = \frac{\text{mass of MgCl}_2}{\text{molar mass of MgCl}_2}
\][/tex]
- Plugging in the values:
[tex]\[
\text{Moles of MgCl}_2 = \frac{0.0750 \, \text{g}}{95.211 \, \text{g/mol}} \approx 0.000787724 \, \text{moles}
\][/tex]
3. Determine the number of moles of chloride ions:
- Each formula unit of MgCl₂ contains 2 chloride ions (Cl⁻).
- Therefore, the number of moles of chloride ions is twice the number of moles of MgCl₂:
[tex]\[
\text{Moles of Cl⁻ ions} = 2 \times \text{Moles of MgCl}_2
\][/tex]
- Substituting the number of moles of MgCl₂:
[tex]\[
\text{Moles of Cl⁻ ions} = 2 \times 0.000787724 \approx 0.001575448 \, \text{moles}
\][/tex]
Thus, there are approximately 0.001575448 moles of chloride ions in 0.0750 g of magnesium chloride.
