Answer:
12 g
Explanation:
We want to prepare 1 L of a 0.15 M NaOH solution. The moles of NaOH required are:
0.15 mol/L × 1 L = 0.15 mol
The molar mass of NaOH is 40.00 g/mol. The mass corresponding to 0.15 mol is:
0.15 mol × (40.00 g/mol) = 6.0 g
The starting solution is 50% by weight. The mass of solution that contains 6.0 g of NaOH is:
6.0 g NaOH × (100 g solution/50 g NaOH) = 12 g solution
