Determinación del Punto de equivalencia de una titulación potenciométrica por el método de la primera derivada:

HCl

0 5 10 15 20 25 30 35 40 450

1

2

3

4

5

6

primera derivada del pH

0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.0002468

101214

7.02

pH vs mL

Volumen de NaOH (mL)

pH d

e la

diso

lució

n

mL NaOH

pH ΔmL derivada del pH

2.00 0.67

4.00 0.72 3.00 0.025

6.00 0.78 5.00 0.03

8.00 0.86 7.00 0.04

10.00 0.96 9.00 0.05

12.00 1.06 11.00 0.05

14.00 1.26 13.00 0.1

16.00 1.40 15.00 0.07

18.00 1.63 17.00 0.115

20.00 2.22 19.00 0.295

21.00 7.02 20.50 4.8

23.00 11.45

22.00 2.215

25.00 11.71

24.00 0.13

27.00 11.79

26.00 0.04

29.00 11.85

28.00 0.03

31.00 11.85

30.00 0

33.00 11.89

32.00 0.02

35.00 11.92

34.00 0.015

37.00 11.95

36.00 0.015

39.00 11.96

38.00 0.005

40.00 11.98

39.50 0.02

HAc

0 5 10 15 20 25 30 35 40 450

0.51

1.52

2.53

3.54

4.55

ΔpH/ΔmL

0 5 10 15 20 25 30 35 40 4502468

101214

10.89

pH vs mL

mL de NaOH

pH

NaOH

mL NaO

HpH

promedio mL

ΔpH/ΔmL

0 2.19

1 2.91 0.5 0.72

2 3.34 1.5 0.43

3 3.59 2.5 0.25

4 3.8 3.5 0.21

5 3.94 4.5 0.14

6 4.08 5.5 0.14

7 4.22 6.5 0.14

8 4.33 7.5 0.11

9 4.44 8.5 0.11

10 4.55 9.5 0.11

11 4.66 10.5 0.11

12 4.78 11.5 0.12

13 4.89 12.5 0.11

14 5.03 13.5 0.14

15 5.15 14.5 0.12

16 5.34 15.5 0.19

17 5.55 16.5 0.21

18 5.85 17.5 0.3

19 6.52 18.5 0.67

20 10.89 19.5 4.37

21 11.35 20.5 0.46

22 11.54 21.5 0.19

23 11.64 22.5 0.1

24 11.72 23.5 0.08

25 11.77 24.5 0.05

26 11.81 25.5 0.04

27 11.85 26.5 0.04

28 11.87 27.5 0.02

29 11.9 28.5 0.03

30 11.92 29.5 0.02

31 11.93 30.5 0.01

32 11.94 31.5 0.01

33 11.96 32.5 0.02

34 11.97 33.5 0.01

35 11.99 34.5 0.02

36 11.99 35.5 0

37 11.99 36.5 0

38 12.01 37.5 0.02

39 12.01 38.5 0

0 5 10 15 20 25 30 35 40 45

-1.6

-1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

ΔpH/ΔmL

0 5 10 15 20 25 30 35 40 450

2

4

6

8

10

12

14

5.92

pH vs mL

mL de HAc

pH

NH3

0 5 10 15 20 25

-6

-5

-4

-3

-2

-1

0

ΔpH/ΔmL

mL de HAc

pH promedio mL

ΔpH/ΔmL

2 12.18

4 12.19

3 0.005

8 12.16

6 -0.0075

10 12.12

9 -0.02

12 12.02

11 -0.05

14 11.91

13 -0.055

16 11.66

15 -0.125

18 10.85

17 -0.405

20 8.73 19 -1.0622 5.92 21 -1.40524 5.46 23 -0.2326 5.24 25 -0.1128 5.06 27 -0.0930 4.94 29 -0.0632 4.83 31 -0.05534 4.76 33 -0.03536 4.69 35 -0.03538 4.64 37 -0.02540 4.59 39 -0.025

mL de HCl

pH promedio mL

ΔpH/ΔmL

1 10.132 9.88 1.5 -0.253 9.67 2.5 -0.214 9.49 3.5 -0.185 9.31 4.5 -0.186 9.08 5.5 -0.237 8.85 6.5 -0.238 8.41 7.5 -0.449 2.79 8.5 -5.62

10 1.82 9.5 -0.9711 1.58 10.5 -0.2412 1.42 11.5 -0.1613 1.3 12.5 -0.1214 1.23 13.5 -0.0715 1.15 14.5 -0.0816 1.1 15.5 -0.0517 1.06 16.5 -0.0418 1.01 17.5 -0.0519 0.98 18.5 -0.0320 0.95 19.5 -0.0321 0.92 20.5 -0.03

0 5 10 15 20 25 30 350

2

4

6

8

10

12

2.79

pH vs mL

mL HCl

pH