Question

question 17 (5 points) steve is performing a titration, where a base is at an unknown concentration. what should he choose as his indicator solution? a) a chemical thats clear when acidic and turns color when basic b) a chemical thats clear when basic and turns color when acidic c) a chemical that buffers the solution d) a chemical that turns color when the temperature changes

Explanation:

In a titration with an unknown - concentration base, we are adding an acid (presumably) to neutralize it. The indicator should show a color change when the base is neutralized (or when the solution becomes acidic enough after neutralizing the base). Option A: If the indicator is clear in acidic (before adding enough acid to neutralize the base, the solution is basic) and turns color in basic, it won't show the end - point (since the solution is already basic). Option B: The indicator is clear in basic (the initial solution with the unknown base is basic, so the indicator is clear) and turns color in acidic. When we add acid and neutralize the base and then add a little more acid, the solution becomes acidic, and the indicator changes color, which is the end - point of the titration. Option C: Buffers are not indicators; they resist pH change, so this is incorrect. Option D: Temperature - dependent color change is not related to acid - base titration end - point detection, so this is incorrect.

Answer:

B) A chemical that’s clear when basic and turns color when acidic