HW 6.65 [ENDORSED]

$E_{cell} = E_{cell}^{\circ}-\frac{RT}{nF}\ln Q$

Hannah Lee 2F
Posts: 117
Joined: Thu Jul 11, 2019 12:15 am

HW 6.65

What range (in volts) does a voltmeter need to have to measure pH in the range of 1 to 14 at 25 C if the voltage is zero when pH = 7?

According to solutions manual, [H+] = 1 when pH = 1.
Why would [H+] not equal 0.10 at pH = 1 (because [H+] = 10^-pH = 10^-1 = 0.10?

Brian_Ho_2B
Posts: 221
Joined: Fri Aug 09, 2019 12:16 am

Re: HW 6.65

Good catch! It appears that this is another error in the solutions manual. You are correct in the fact that a pH of 1 means that [H+] = 0.1M. Other than that, you should be able to solve the rest of the problem. Remember to use the Kw value of water to find [OH-] values to calculate your Q in the Nernst equation.

Chem_Mod
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Re: HW 6.65  [ENDORSED]

6.65 has a typo.

Should read: At pH = 0 (not “At pH = 1”)

The normal pH scale is 0-14.

I am updating the file: Solution Manual Errors 7th Edition
https://lavelle.chem.ucla.edu/wp-conten ... rs_7Ed.pdf

Good posts! :-)

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