# You make two liters of a 3.0 pH solution of H2SO4:

You make 2 liters of a 3.0 pH solution of H2SO4:

1. how much water will i need to add to make the pH4.0 / 5.0?

2. How many more times more dilute is a 1.0 pH solution than the original?

3. What is the concentration of [h+] in the 1.0 pH solution and in the 3.0 ph solution?

4. If you have one mole of H2SO4, How many hydrogen ions are there? sulfate ions?

Chat with an Online Tutor

Get help immediately by chatting with an live tutor right now

Get help immediately by chatting with an live tutor right now

**If you find this answer useful please share it with other students.**

mle219 wrote:If they told you it's a strong acid, you really would not need to know which acid it was to answer this part.

A strong acid is completely dissociated into ions in the pH range of 1.0 to 5.0.

Also, in that pH range, the amount of H

^{+}ions contributed by water will be insignificant compared to the amount coming from the acid.As a consequence, you can assume that all the H

^{+}in solution comes from H_{2}SO_{4}, and that all the H in H_{2}SO_{4}is in solution as H^{+}ions, before, and after diluting.You only need to know the concentrations of H

^{+}ions.Since pH = -log[H

^{+}], [H^{+}] = 10^{-pH}So, for pH = 3.0, H

^{+}] = 10^{-3.0}M = 0.001MFor pH = 4.0 and 5.0, you can calculate [H

^{+}] similarly.Once you know the concentrations before and after, you can easily calculate how much to dilute.

For example, if you needed to dilute to 0.0001M, since the pH = 3.0 solution is 0.001M, you would be diluting 10 times. The final volume would be 20 liters. You would have to add 18 more liters.

KMST

Thu, 2011-06-02 21:07

mle219 wrote:What do you mean by the original? Is it the pH=3.0 solution?

And what is a 1.0 pH solution? Did you mean a solution 1.0 higher in pH?

A pH=1.0 solution would be much more concentrated than a pH=3.0 solution.

Within limits, each increase of 1.0 units in pH means a solution ten times more dilute. The "limits" are in that at less than pH=1.0, even a strong acid may not be quite 100% dissociated, and that at pH>5 the H

^{+}and OH^{-}ions contributed by water would matter, and you could never get to pH>7 just by diluting an acid.mle219 wrote:In a solution with pH=1.0, [H

^{+}], the concentration of H^{+}, would be 0.1M,pH = -log[H

^{+}], and[H

^{+}] = 10^{-pH}KMST

Thu, 2011-06-02 21:27