Question

What is the method to prepare a 0.005 molar solution of acid in a 250 ml volumetric flask using 25 ml of a 2 M solution?

A) Dilute 25 ml of the 2 M solution with distilled water to fill the 250 ml flask.
B) Concentrate the 25 ml of the 2 M solution by evaporating excess water and then add 225 ml of distilled water.
C) Mix 25 ml of the 2 M solution with 225 ml of distilled water in the 250 ml flask.
D) Add 25 ml of the 2 M solution to the 250 ml flask and then top it up with an additional 225 ml of 2 M solution.

Answer 1

To prepare a 0.005 molar solution of acid in a 250 ml volumetric flask using 25 ml of a 2 M solution, you should dilute 25 ml of the 2 M solution with distilled water to fill the flask.

Step-by-step explanation:

The method to prepare a 0.005 molar (M) solution of acid in a 250 ml volumetric flask using 25 ml of a 2 M solution is to dilute it with distilled water. Using the dilution equation M1V1 = M2V2, where M1 is the initial molarity, V1 is the volume of the initial concentrated solution, M2 is the final molarity, and V2 is the final volume of the solution, we can calculate the appropriate method. In this case, we multiply the initial molarity (2 M) by the initial volume (25 ml) to get the number of moles of solute, and then we want to set it equal to the desired final concentration (0.005 M) times the final volume (250 ml). Doing the math, we find that V2 is indeed 250 ml, confirming that the correct option is 'A': Dilute 25 ml of the 2 M solution with distilled water to fill the 250 ml flask.