<p>IDK about you guys, but I feel the the Acid Bases chapter in PR is the most obfuscating chapter in the entire book. does PR go too far in this specific chapter than what will actually be on the SAT II test?</p>
<p>can someone try and explain to me the deal with the exponents and OH concentration, as asked in the last question of the MC? im confusing that with the pH. The way I'm thinking about it is as OH is greater than 1.0 x 10^-7, then pH is less than 1.0 x 10^-7. </p>
<p>Can someone please sum this concept up in a understandable,yet thorough manner?</p>
<p>Thanks!</p>
<p>When they give you an OH concentration, and ask for pH, you need to do some conversions. You can either use:
1) Kw (water's autoionization constant) = 1.0<em>10^-14=[H+]</em>[OH-]<br>
You solve for [H+], then plug in the numbers to get [H+], ie
1.0*10^-14/[OH-] = [H+]</p>
<p>2) pH + pOH = 14
For this, find the pOH given your [OH-] concentration (pOH = -log(10)[OH-]
Then you plug that into the rearranged formula pH= 14-pOH</p>
<p>I can't tell exactly what you're saying with your last sentence, but it looks like you're confusing high exponent numbers (ie 1&10^-10) with high concentrations. Remember when the exponent increases in the negative direction, that means the number is getting smaller.</p>
<p>That chapter is really confusing, and you don't need to know a lot of it. Just know which acids and bases are strong ones and the post above mine's #2.</p>