Question

You are given a 2M stock solution of NaCl and are asked to make up 100 ml of a 1M solution of NaCl. How do you do that, using the stock solution and distilled water? Select one: O a. I would add 2 ml of the stock to 98 ml of water. O b. I would add 10 ml of the stock to 40 ml of water O c. I would add 20 ml of the stock to 80 ml of water. O d. I would add 50 ml of the stock to 50 ml of water.

Answer 1

The correct answer is d) I would add 50 ml of the stock to 50 ml of water.

Explanation:

Guven, Intial stock concentration (5) = 2M. Pinal stock concentration (S2) - 1 Final volume (V2) = 100 me Intial volume (vi) = ? M We know that Vesi = V2 S2 or vi = 8252 si 2 100x 1M = 50 ml 2 M Water, 2-V1 = (100-50) = 50 me water Therefore, I would add 50 ml of the stock to 50 me of water to make 100 oul of 1M solution of Nall.