Wrong results to log .00008? I get 9.4, it should be 4.08

I'm doing this:
pOH= -log .00008 (four zeros)
pOH= - -9.4
pOH= 9.4

But that result is wrong, it should be 4.08. Where I'm wrong?

log base 10 of 0.00008 means 10 raised to what power gives 0.00008
That's just the definition of log.


10^(-4) = 0.0001
10^(-5) = 0.00001

So the true result must be somewhare between -4 and -5.

When I did this with natural log, I got -9.43
Here, you need to use log base 10, not log base e which is ln

pH is measured in terms of base 10.

I think that is where your error is.

log[10](0.8e-4) = - 4.096910013

ln(0.8e-4) = - 9.433483923