Question

3. In the figure below, titration curves for strong acid with strong base and weak acid with strong base are shown. Compare the shapes of these curves early in the titration for th ree different cases: titration of a strong acid, titration of a weak acid with a lower pKa, and titration of a weak acid with a higher pKa. Discuss with the class why the titration curve for weak acids increase more rapidly early in the titration than do stronger acids. Titration of Strong Acid Titration of Weak Acid 14- 14 13 13 12 12 11 11 10- 10 Equivalence point pH, 8.72 9 9 8- 8 Equivalence point pH, 7.00 7 품7 6 6 5 5 4 4 3. 3 2 2 1 1 5 10 15 20 25 30 35 40 45 50 O 5 10 15 20 25 30 35 40 45 50 Volume of 0.100 M NaOH added (mL) Volume of 0.100 M NaOH added (mL) (a) (b)

Question: In the figure below, titration curves for strong acid with strong base and weak acid with strong base are shown. Compare the shapes of these curves early in the titration for three different cases: titration of a strong acid, titration of a weak acid with a lower pKa, and titration of a weak acid with a higher pKa. Discuss with the class why the titration curve for weak acids increase more rapidly early in the titration than do stronger acids."

Please answer this question with a nice detailed response. Thanks

Answer 1

1) Titration of strong acid

( a )titration curve in this case is S - shaped. Titration curve is asymmetric.

(b ) at equivalence point solution is neutral and P^H = 7 at 25 ^o C

( c ) shape of titration curve depend on concentration of strong acid / base it does not depend over their identity.

( d ) there is sharp change in P^H near equivalence point and we have wide range of choices of indicators to detect equivalence point.

2) Titration of weak acid

( a) titration curve of weak acid depend over its K_a value along with their concentration.

( b )P^H changes gradually near equivalence point not as sharply as in case of strong acid

( c ) In weak acid titration equivalence point has p^H greater  than 7.

( d ) in weak acid lower P^ka value means acid is relatively strong and P^H change will be slow in beginning and sharp near equivalence point than acid having higher P^ka value.

titration curve of weak acid increases more rapidly since it is weakly ionised and have less concentration of H⁺ ion.
Comparison of raph acidl s Wea K ad wih P NaOH