Question

A solution of pH 5 is diluted 100 times. Find the pH of the resulting solution.

Answer 1

First, we calculate of the concentration of the H+ ions in the solution from the pH given. Then, calculate the new concentration after dilution. Calculation are as follows:

pH = -log[H+]
5 = -log[H+]
[H+] = 1 x 10^-5 M

M1V1 = M2V2
1 x 10^-5 M (V1) = M2(100V1)
M2 = 1 x 10^-7

pH =  -log[1 x 10^-7]
pH = 7

Answer 2

Answer:

The pH of the resulting solution is 7. This means that the solution is neutral.

Explanation:

To reach the pH of the resulting solution some calculations are required. They are simple calculations and you can use a calculator to help. Well, first you have to find out the concentration of hydrogen atoms that the solution had before it was diluted, for that you will use the formula pH = -log [H +]. Substituting the values in the formula, we have:

pH = -log [H +]

5= 5 = -log [H +]

[H +] = 1 x 10 ^ -5 M

Once you find this value, you will find the H + atom concentration after dilution using the formula C1V1 = C2V2. Substituting the values in the formula we will have:

C1V1 = C2V2

1 x 10 ^ -5 M (V1) = M2 (100V1)

M2 = 1x10 ^ -7

You can now reuse the first formula to finally find the pH of this solution after all dilution. The calculation will be:

pH = -log [1 x 10 ^ -7]

pH = 7