If Luke mixes 20g of NaOH(formula wt. of 40g/mol) with enough water to make 500mL of solution (1L= 1000mL); what is the Molarity (M) of the solution (SW)

Question

If Luke mixes 20g of NaOH(formula wt. of 40g/mol) with enough water to make 500mL of solution (1L= 1000mL); what is the Molarity (M) of the solution (SW)

Answer 1

Molarity (M) is defined as moles of solute per liter of solution

Find moles of solute:

20 g NaOH x 1 mol NaOH/40 g = 0.5 moles NaOH

Liters of solution = 500 ml x 1 L/1000 ml = 0.5 L

Molarity = 0.5 moles NaOH/0.5 L solution = 1.0 M