<p>Can somebody explain ^ numbers 33 and 34. Buffers/Titrations are not really my strong suit and I was gone the days my teacher explained them.</p>
<p>33 is D. You can see on the titration graph that there is a steep slope between points W and Y. That is where the equivalence point is, meaning an equivalent amount of H+ and OH-. The center of this slope is ~8.0 pH. Thus, you must pick an indicator with an end point of ~8.0pH. This would be D.</p>