Question

Your stock solution is 10M NaCl. You want to make a 350mL solution of 450mm NaCl. How would you make this solution? Add 15.75 mL of water and 334.25 stock NaCl solution Add 15.75 mL of stock NaCl solution and 334.25 ml water Add 157.5 mL of stock NaCl solution and 192.5 ml water Add 157.5 mL of water and 192.5 mL stock NaCl solution

Answer 1

We will use the formula-

M1V1 = M2V2

10X10^-3 = 350X450

So, 350x450/ 10x10^-3

= 15.75 ml of stock solution

Total we need 350 ml solution so we will use 15.75 ml of the stock solution and 334.25 ml of water.

A is incorrect as we will not use 334.25ml of stock solution.

B is correct as we will use 15.75 ml of stock solution.

C is incorrect as we will not use 157.5 ml of stock solution.

D is incorrect as we will not use 192.5 ml of stock solution.

So, the correct answer is B.