Question

What volume of water is needed to dilute 10.0 mL of 2.0 M HCl to make a 0.25 M HCl solution?

A. Enough to make 50. ml of solution
B. Enough to make 60. mL of solution
C. Enough to make 70. mL of solution
D. Enough to make 80. mL of solution

Answer 1

The answer for that would be D. 80 mL

Answer 2

D. 80 mL

Explanation:

Given:

- 10.0 mL of HCL

- 2.0 M HCl

- .25 M HCl

1) Convert mL to L

10 mL/1000 mL = .01 L

2) Find # of moles of HCl

2.0 M HCl = (x/.01 L)

x = .02 mol HCl

3) Find volume needed to make .25 M HCl

.25 M = .02 mol HCl/ y

y = .08 Liters

4) Convert Liters to mL

.08 L * 1000 mL = 80 mL

Answer: 80 mL (D)