# Simple Algerbraic Manipulation is Confusing Me

1. Feb 4, 2008

### mrlucky0

I'm working on a chemistry problem and I'm trying to follow the derivation for % ionization (of a weak acid or base) but I can't seem to understand how rearrangement of eq. 6 results in eq. 7.

In more general terms, I started with the Hendreson Hasselbalch equation:

pH = pka + log(A-/AH)

What I want to find is, A-/(AH + A-)

This is giving me a real headache, can anyone help?

File size:
4.6 KB
Views:
53
2. Feb 5, 2008

### neutrino

Bring the A- to the LHS of (6). Add 1 to both sides and convert the LHS to a single fraction. Invert the fractions and multiply by 100.

3. Feb 5, 2008

### mrlucky0

Thanks, I've got it now.