Calculate the molarity of a 23.55-mL solution which contains 28.24 mg of sodium sulfate (used in dyeing and printing textiles, ℳ = 139.04 g/mol).
A)8.625 M
B)1.199 M
C)0.8339 M
D)0.2031 M
E)0.008625 M

Question

Quizplus · Accepted Answer

First, convert the mass of sodium sulfate to moles: $ \frac{28.24 \, \text{mg}}{1000} = 0.02824 \, \text{g} $; $ \text{moles} = \frac{0.02824 \, \text{g}}{139.04 \, \text{g/mol}} = 0.0002031 \, \text{mol} $. Then, convert the volume of the solution to liters: $ 23.55 \, \text{mL} = 0.02355 \, \text{L} $. Finally, calculate molarity: $ \text{Molarity} = \frac{0.0002031 \, \text{mol}}{0.02355 \, \text{L}} = 0.008625 \, \text{M} $.

Calculate the Molarity of a 23