Answer:
The correct answer is B. 734 g
Step-by-step explanation:
The chemical formulae of lithium sulfate is Li₂SO₄. With this, we can calculate the molecular weight (MM) of lithium sulfate as follows:
MM(Li₂SO₄) = (2 x molar mass Li) + molar mass S + (4 x molar mass O)
= (2 x 6.9 g/mol) + 32 g/mol + (4 x 16 g/mol)
= 109.9 g/mol
We need to prepare a solution with a molarity of 2.67 M. That means that the solution has to have 2.67 moles of Li₂SO₄ per liter of solution. We can convert from mol to grams with the calculated molecular weight and then we have to multiply by the volume of solution (2500 ml= 2.5 L), as follows:
Mass = 2.67 mol/L x 109.9 g/mol x 2.5 L ≅ 734 g