What mass of MgBr2 (in grams) is present in 215 mL of a 0.350 M solution of MgBr2?

• A. 6.4 g
• B. 8.2 g
• C. 21.0 g
• D. 13.5 g

Answer: (D)

Verified step by step guidance

1. Identify the given information: volume of solution = 215 mL, molarity (M) = 0.350 mol/L, and the solute is MgBr\_2.
2. Convert the volume from milliliters to liters because molarity is expressed in moles per liter: \(\text{Volume (L)} = \frac{215}{1000}\).
3. Calculate the number of moles of MgBr\_2 using the molarity formula: \(\text{moles} = M \times \text{Volume (L)} = 0.350 \times \frac{215}{1000}\).
4. Determine the molar mass of MgBr\_2 by adding the atomic masses of magnesium and bromine: \(\text{Molar mass} = \text{atomic mass of Mg} + 2 \times \text{atomic mass of Br}\).
5. Calculate the mass of MgBr\_2 by multiplying the moles by the molar mass: \(\text{mass} = \text{moles} \times \text{molar mass}\).