Question

ISSSSSSSSSSSSSS NEEBS HELPZZZ

Using the formula M1V1=M2V2, how many mL of stock solution of 2M NaCl do you need to prepare 100mL of 0.15 M NaCl?

Question 10 options:

1333 mL


15 mL


200 mL


7.5 mL

Answer 1

We can use the formula M1V1 = M2V2 to find the volume of the 2M NaCl stock solution needed to prepare 100 mL of 0.15M NaCl solution.

M1 = 2M (the concentration of the stock solution)

V1 = unknown (the volume of stock solution we need to use)

M2 = 0.15M (the desired concentration of the final solution)

V2 = 100mL (the volume of the final solution)

Plugging in the values, we get:

2M x V1 = 0.15M x 100mL

Simplifying, we get:

V1 = (0.15M x 100mL) / 2M

V1 = 7.5mL

Therefore, we need to use 7.5 mL of the 2M NaCl stock solution to prepare 100 mL of 0.15 M NaCl solution.

The correct answer is option D: 7.5 mL.

Answer 2

We can use the formula M1V1 = M2V2 to find the volume of the 2M NaCl stock solution needed to prepare 100 mL of 0.15M NaCl solution.

M1 = 2M (the concentration of the stock solution)
V1 = unknown (the volume of stock solution we need to use)
M2 = 0.15M (the desired concentration of the final solution)
V2 = 100mL (the volume of the final solution)

Plugging in the values, we get:

2M x V1 = 0.15M x 100mL

Simplifying, we get:

V1 = (0.15M x 100mL) / 2M

V1 = 7.5mL

Therefore, we need to use 7.5 mL of the 2M NaCl stock solution to prepare 100 mL of 0.15 M NaCl solution.

The correct answer is option D: 7.5 mL.