Question

Determine how many ml of water you need to remove, by evaporation, if you have 1000 ml of 9 M HCl dilute solution and you need to make it a 12 M HCl stock solution.

a) 125 ml
b) 150 ml
c) 175 ml
d) 200 ml

Answer 1

To make a 1000 ml 9 M HCl dilute solution a 12 M HCl stock solution, you need to remove 250 ml of water by evaporation.

Step-by-step explanation:

To determine how many mL of water you need to remove by evaporation from a dilute solution of HCl, you can use the equation for dilution: M1V1=M2V2. In this case, the initial molarity (M1) is 9 M, the final molarity (M2) is 12 M, and the initial volume (V1) is 1000 mL. We can rearrange the equation to solve for V2, the final volume:

12 M × V2 = 9 M × 1000 mL

V2 = (9 M × 1000 mL) / 12 M

V2 = 750 mL

Therefore, you need to remove 250 mL of water from the solution by evaporation. The correct answer is (b) 250 ml.