What is the % by mass of sodium chloride in an aqueous solution that is 2.39 M and has a density of 1.01 g/mL?
A)2.36
B)13.8
C)7.83
D)140.
E)19.6

Question

Quizplus · Accepted Answer

To find the % by mass of sodium chloride in the solution, we first need to calculate the mass of sodium chloride in a given volume of the solution and then calculate the total mass of the solution for the same volume. The molarity (M) gives us moles of solute per liter of solution. 1. Calculate the mass of NaCl in 1 L of solution:$$ \text{Molarity (M)} = 2.39 \, \text{mol/L} $$The molar mass of NaCl is approximately $58.44 \, \text{g/mol}$.$$ \text{Mass of NaCl} = 2.39 \, \text{mol/L} \times 58.44 \, \text{g/mol} = 139.66 \, \text{g} $$2. Calculate the mass of 1 L of solution:Given the density is $1.01 \, \text{g/mL}$, for $1000 \, \text{mL}$ (or 1 L), the mass of the solution is:$$ \text{Mass of solution} = 1.01 \, \text{g/mL} \times 1000 \, \text{mL} = 1010 \, \text{g} $$3. Calculate the % by mass of NaCl:$$ \% \, \text{by mass} = \frac{\text{Mass of NaCl}}{\text{Mass of solution}} \times 100 = \frac{139.66 \, \text{g}}{1010 \, \text{g}} \times 100 \approx 13.8\% $$Therefore, the % by mass of sodium chloride in the solution is approximately 13.8%.

What Is the % by Mass of Sodium Chloride in an Aqueous