Subject: negative logs
Name: Brenda Miskimmin
-log M (Hg) = 8.5
where mw of Hg=200.59
(it's the negative sign in front of log that confuses me).
I am not sure what you are doing but I can interpret the negative sign in front of the log. It comes from the fact that log(ab) = b log(a). In your case you have b = -1 so -log(a) = (-1) log(a) = log(a-1) = log(1/a)