Question

In: Chemistry

Determine the pH during the titration of 56.0 mL of 0.389 M hydrofluoric acid (Ka =...

Determine the pH during the titration of 56.0 mL of 0.389 M hydrofluoric acid (Ka = 7.2×10-4) by 0.389 M NaOH at the following points. (Assume the titration is done at 25 °C.)

(a) Before the addition of any NaOH

(b) After the addition of 14.0 mL of NaOH

(c) At the half-equivalence point (the titration midpoint)

(d) At the equivalence point

(e) After the addition of 84.0 mL of NaOH

Solutions

Expert Solution

pKa = -log Ka

pKa = 3.14

(a) Before the addition of any NaOH

pH = 1/2 [pKa - log C]

pH = 1/2 [3.14 - log 0.389]

pH = 1.78

(b) After the addition of 14.0 mL of NaOH

millimoles of HF = 56.0 x 0.389 = 21.8

millimoles of NaOH = 0.389 x 14 = 5.45

HF    +    NaOH -------------------------> NaF + H2O

21.8           5.45                                    0         0

16.4           0                                        5.45   

pH = pKa + log [NaF/ HF]

pH = 3.14 + log (5.45 / 16.4)

pH = 2.66

(c) At the half-equivalence point (the titration midpoint)

here pH = pKa

pH = 3.14

(d) At the equivalence point

salt concentration =- 56 x 0.389 / (56 +56)

                             = 0.504 M

pH = 7 + 12/ [pKa + logC]

pH = 7 + 1/2 [3.14 + log 0.504]

pH = 8.42

(e) After the addition of 84.0 mL of NaOH

answer : 12.9

queen_honey_blossom answered 3 years ago
Next > < Previous

Related Solutions

Determine the pH during the titration of 56.9 mL of 0.385 M hydrofluoric acid (Ka =...
Determine the pH during the titration of 56.9 mL of 0.385 M hydrofluoric acid (Ka = 7.2×10-4) by 0.385 M NaOH at the following points. (a) Before the addition of any NaOH (b) After the addition of 14.0 mL of NaOH (c) At the half-equivalence point (the titration midpoint) (d) At the equivalence point (e) After the addition of 85.4 mL of NaOH
Determine the pH during the titration of 24.3 mL of 0.310 M formic acid (Ka =...
Determine the pH during the titration of 24.3 mL of 0.310 M formic acid (Ka = 1.8×10-4) by 0.442 M NaOH at the following points. (a) Before the addition of any NaOH (b) After the addition of 4.20 mL of NaOH (c) At the half-equivalence point (the titration midpoint) (d) At the equivalence point (e) After the addition of 25.6 mL of NaOH
Determine the pH during the titration of 65.9 mL of 0.410 M hypochlorous acid (Ka =...
Determine the pH during the titration of 65.9 mL of 0.410 M hypochlorous acid (Ka = 3.5×10-8) by 0.410 M NaOHat the following points. (a) Before the addition of any NaOH-? (b) After the addition of 16.0 mL of NaOH-? (c) At the half-equivalence point (the titration midpoint) -? (d) At the equivalence point -? (e) After the addition of 98.9 mL of NaOH-?
Determine the pH during the titration of 66.6 mL of 0.468 M hypochlorous acid (Ka =...
Determine the pH during the titration of 66.6 mL of 0.468 M hypochlorous acid (Ka = 3.5×10-8) by 0.468 M NaOH at the following points. (Assume the titration is done at 25 °C.) (a) Before the addition of any NaOH ? (b) After the addition of 16.0 mL of NaOH ? (c) At the half-equivalence point (the titration midpoint) ? (d) At the equivalence point ? (e) After the addition of 99.9 mL of NaOH ?
Determine the pH during the titration of 62.1 mL of 0.445 M benzoic acid (Ka =...
Determine the pH during the titration of 62.1 mL of 0.445 M benzoic acid (Ka = 6.3×10-5) by 0.445 M NaOH at the following points. (Assume the titration is done at 25 °C.) (a) Before the addition of any NaOH (b) After the addition of 15.0 mL of NaOH (c) At the half-equivalence point (the titration midpoint) (d) At the equivalence point (e) After the addition of 93.2 mL of NaOH
Determine the pH during the titration of 22.7 mL of 0.406 M hydrocyanic acid (Ka =...
Determine the pH during the titration of 22.7 mL of 0.406 M hydrocyanic acid (Ka = 4.0×10-10) by 0.492 M KOH at the following points. (a) Before the addition of any KOH (b) After the addition of 4.60 mL of KOH (c) At the half-equivalence point (the titration midpoint) (d) At the equivalence point (e) After the addition of 28.1 mL of KOH
Determine the pH during the titration of 24.3 mL of 0.310 M formic acid (Ka =...
Determine the pH during the titration of 24.3 mL of 0.310 M formic acid (Ka = 1.8×10-4) by 0.442 M NaOH at the following points. (a) Before the addition of any NaOH (b) After the addition of 4.20 mL of NaOH (c) At the half-equivalence point (the titration midpoint) (d) At the equivalence point (e) After the addition of 25.6 mL of NaOH
Determine the pH during the titration of 73.5 mL of 0.429 M acetic acid (Ka =...
Determine the pH during the titration of 73.5 mL of 0.429 M acetic acid (Ka = 1.8×10-5) by 0.429 M KOH at the following points. (Assume the titration is done at 25 °C.) (a) Before the addition of any KOH (b) After the addition of 17.0 mL of KOH (c) At the half-equivalence point (the titration midpoint) (d) At the equivalence point (e) After the addition of 110 mL of KOH
Determine the pH during the titration of 24.8 mL of 0.475 M nitrous acid (Ka =...
Determine the pH during the titration of 24.8 mL of 0.475 M nitrous acid (Ka = 4.5×10-4) by 0.361 M NaOH at the following points. (a) Before the addition of any NaOH __________ (b) After the addition of 8.20 mL of NaOH __________ (c) At the half-equivalence point (the titration midpoint) ________ (d) At the equivalence point __________ (e) After the addition of 48.9 mL of NaOH __________
Determine the pH during the titration of 66.6 mL of 0.457 M acetic acid (Ka =...
Determine the pH during the titration of 66.6 mL of 0.457 M acetic acid (Ka = 1.8×10-5) by 0.457 M KOH at the following points. (Assume the titration is done at 25 °C.) a.) Before the addition of any KOH b.)  After the addition of 16.0 mL of KOH c.) At the half-equivalence point (the titration midpoint) d.) At the equivalence point e.) After the addition of 99.9 mL of KOH Thank you!!
ADVERTISEMENT
Subjects
ADVERTISEMENT
Latest Questions
ADVERTISEMENT