The molarity of a solution prepared by dissolving 15.0 grams of NaCl in 1000 mL water is 0.15M .

Question

Quizplus · Accepted Answer

Molarity (M) is defined as the number of moles of solute per liter of solution. To calculate the molarity of NaCl solution, we need to first convert the given mass of NaCl to moles.

Number of moles of NaCl = mass of NaCl / molar mass of NaCl
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol (sum of atomic masses of Na and Cl)

Number of moles of NaCl = 15.0 g / 58.44 g/mol = 0.256 moles

Now, we need to calculate the volume of solution in liters:

1000 mL = 1000/1000 L = 1 L

Thus, the molarity of the solution is:

Molarity = number of moles of solute / volume of solution in liters
Molarity = 0.256 moles / 1 L = 0.256 M

Therefore, the molarity of the solution is 0.256 M, not 0.15 M. Hence, the given statement is false and the answer is B.

The Molarity of a Solution Prepared by Dissolving 15