Lecture 183/2/07

QUIZ 1. True or False: Buffer solutions are always at pH For each pair, which will have a lower pH? M HFor0.1 M NaF M HNO 3 or 0.1 M HNO M HNO 3 or 0.1 M HF M NH 3 or 0.1 M NaF M H 2 Sor 0.1 M H 2 Se

Equivalence point (NaOH titrating HF) X-axis Y-axis

Building a titration curve via calculations Comparison of a titration of a strong acid vs. a weak acid Region x-axis (mL of acid/base) 0.1 M NaOH y-axis (pH) 100 mL of 0.1 M HCl y-axis (pH) 100 mL of 0.1 M HF Initial pH Before the equivalence point (1/2 equiv. point) equivalence point After the equivalence point

½ Equivalence point (NaOH titrating HF) X-axis Y-axis

Building a titration curve via calculations Comparison of a titration of a strong acid vs. a weak acid Region x-axis (mL of acid/base) 0.1 M NaOH y-axis (pH) 100 mL of 0.1 M HCl y-axis (pH) 100 mL of 0.1 M HF Initial pH Before the equivalence point (1/2 equiv. point) equivalence point After the equivalence point

After Equivalence point (NaOH titrating HF) X-axis Y-axis

Building a titration curve via calculations Comparison of a titration of a strong acid vs. a weak acid Region x-axis (mL of acid/base) 0.1 M NaOH y-axis (pH) 100 mL of 0.1 M HCl y-axis (pH) 100 mL of 0.1 M HF Initial pH Before the equivalence point (1/2 equiv. point) equivalence point After the equivalence point

Titration of a polyprotic acid

Give the identity and concentration of the titrated sample (50 mL) represented by the blue line. KbKb Hydroperoxide 4.2 x Ammonia 1.8 x Hypochlorite 2.86 x Pyridine 1.5 x Aniline 4 x

Optional Spring Break Quizzes 1. 1-page essay - how chemistry impacted you during spring break Both due on Monday after Spring Break

4. (10 points) Given the following titration curve, what is the concentration of a 25-mL weak acid solution titrated with 0.1 M NaOH?