A 10 M concentrated stock solution of NaCl is used to prepare 2 liters of diluted 1 M solution. Which of the following is true for the process used to achieve the required dilution? The volume of the solvent used is less than 2 liters. The volume of the solvent used is less than 0.1 liters. The volume of stock solution used is more than 2 liters. The volume of stock solution used is less than 0.1 liters.

The volume of the solvent used is less than 2 liters.

Explanation:

It is known that the no. of millimoles of the solution before dilution is equal to the no. of millimoles of the solution after the dilution.

(MV) before dilution = (MV) after dilution.

M before dilution = 10.0 M, V before dilution = ? L.

M after dilution = 1.0 M, V after dilution = 2.0 L.

∴ V before dilution = (MV) after dilution / (M) before dilution = (1.0 M) (2.0 L) / (10.0 M) = 0.2 L = 200.0 mL.

So, to prepare the diluted solution; we use 200 mL (0.2 L) from the stock solution (10.0 M NaCl) and add 1.8 L of the solvent (water).

Thus, the right choice is: The volume of the solvent used is less than 2 liters.