## 7th edition 6.57

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

paytonm1H
Posts: 74
Joined: Fri Sep 28, 2018 12:18 am

### 7th edition 6.57

6.57 asks for the Ka value for HF given the two half reaction reduction potentials. After calculating K using the Nernst equation, the solutions manual takes the square root of K to get the Ka value. Can someone explain why they do this?
Thanks!

Matthew Tran 1H
Posts: 165
Joined: Fri Sep 28, 2018 12:16 am

### Re: 7th edition 6.57

They take the square root because K is for the reaction 2HF --> 2H+ + 2F-, but Ka is for the reaction HF <--> H+ + F-. Since the reaction for Ka is half of that of K, Ka is the square root of K.

Return to “Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)”

### Who is online

Users browsing this forum: No registered users and 1 guest