## Textbook 6b1

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Ethan Goode 2H
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### Textbook 6b1

6B.1 The molar concentration of HCl in hydrochloric acid is reduced to 12% of its initial value by dilution. What is the difference in the pH values of the two solutions?
How do you do this problem? I am confused where to start.

Stuti Pradhan 2J
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### Re: Textbook 6b1

The easiest way to do this problem is to simply choose a molar concentration of HCl and find the pH. Then, take 12% of that molar concentration and find the pH value. Subtract the values to find the difference in pH.

For example, I used a 0.5 M solution of HCl, and then a 0.06 M solution (which is 12% of 0.5M), found the two pHs and then found the difference between them.

Hope this helps!

Catie Donohue 2K
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### Re: Textbook 6b1

I couldn't find the solution for this in the textbook - would the correct answer be ~0.921?

Sofia Lombardo 2C
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### Re: Textbook 6b1

The way I approached this problem was to use $\Delta pH = final - initial$. So 0.12 [HCl] - [HCl] and then I took the -log of this value and divided by the initial [HCL] (because it is property of log functions) and then the [HCl] would cancel and I was left with just -log(0.12). $\Delta pH = -log(\frac{0.12[HCl]]}{[HCl]})$

Eric Cruz 2G
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### Re: Textbook 6b1

For this problem I used 1M concentration as the original. Therefore, if you put it in the -log(H) equation, you get 0. 12% of 1M is 0.12M, so I put 0.12 in the -log(H) equation as well and got me 0.92 . I took the difference of the two which is merely just 0.92

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