Don't know if this helps or not... but the - log stuff can sometimes be solved with this trick.

if something has a H+ of 1.0 x 10^-4, you know you just take the power of it and thats yours pH. If its something bigger than 1 and less than 10, then you take the power, subtract it by one, and whatever you are multiplying just subtract that number by 10.

like 4.0 x 10^-8... subtract that 8 by 1 so you get 7. something... subtract 4 from 10 and you get 6. so your answer is pH = 7.6, or something close enough to that.

if you are given the pH, you do the opposite. so if the pH is 11.4, you know the exponent will be 10^-12, and the 4 part subtracted by 10 is going to be 6. so your H+ should be 6 x 10^-12.

works the same for [OH-], pOH, Ka's and pKa's. if the Ka is 1.9 x 10^-6, then the pKa is going to be 5.81

hope that helps.