1. Find the molar mass of MgCl₂

* Mg (Magnesium) has a molar mass of 24.31 g/mol

* Cl (Chlorine) has a molar mass of 35.45 g/mol

* MgCl₂ has a molar mass of 24.31 + (2 * 35.45) = 95.21 g/mol

2. Use the formula:

* Moles = Mass / Molar Mass

3. Plug in the values:

* Moles = 313 g / 95.21 g/mol

* Moles ≈ 3.29 mol

Therefore, there are approximately 3.29 moles of MgCl₂ in 313 g of the compound.