Page **1** of **1**

### 6A.19

Posted: **Mon Jan 13, 2020 11:35 pm**

by **Connor Ho 1B**

Calculate the molar concentration of OH^{−} in solutions with the following molar concentrations of H_{3}O^{+}:

c) 3.1 M

In the solutions manual, it says you divide 10^{-14} by 3.1 x 10^{-3} to get 3.2 x 10^{-12}. Is this an error with the solutions manual/textbook (because the molarity of H_{3}O^{+} does not match between the solutions manual/textbook), or am I missing something to calculate the OH^{-} concentration?

### Re: 6A.19

Posted: **Mon Jan 13, 2020 11:42 pm**

by **Prasanna Padmanabham 4I**

that's confusing...hmm...did it say millimolars? I'm interested in an answer too...

### Re: 6A.19

Posted: **Mon Jan 13, 2020 11:44 pm**

by **nicolely2F**

Pretty sure the textbook question should be 3.1x10^-3 instead of just 3.1, since all the units are the same (L) and it's otherwise just plugging numbers in.

### Re: 6A.19

Posted: **Tue Jan 14, 2020 12:09 am**

by **Subashni Rajiv 1K**

Yeah, when I did this problem, I got 3.2x10^-15.

### Re: 6A.19

Posted: **Tue Jan 14, 2020 1:33 am**

by **Ryan Lee 1E**

I got a 10^-15 value as well. Seems the solutions manual is off.

### Re: 6A.19

Posted: **Tue Jan 14, 2020 10:08 am**

by **Jessica Esparza 2H**

I was looking at this too! Either they forgot to add mM to the problem or it is an error in the solutions manual. I got the answer to the ^-15.

### Re: 6A.19

Posted: **Tue Jan 14, 2020 11:55 pm**

by **Donna Nguyen 2L**

I was having the same problem! It's probably just a mistake in the solutions manual.