1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Hunter-Best [27]
3 years ago
14

A buffer solution contains 0.306 M C6H5NH3Br and 0.418 M C6H5NH2 (aniline). Determine the pH change when 0.124 mol HCl is added

to 1.00 L of the buffer.
Chemistry
1 answer:
Ulleksa [173]3 years ago
8 0

<u>Answer:</u> The pH change of the buffer is 0.30

<u>Explanation:</u>

To calculate the pH of basic buffer, we use the equation given by Henderson Hasselbalch:

pOH=pK_b+\log(\frac{[\text{conjugate acid}]}{[\text{base}]})

pOH=pK_b+\log(\frac{[C_6H_5NH_3^+]}{[C_6H_5NH_2]})        .....(1)

We are given:

pK_b = negative logarithm of base dissociation constant of aniline  = 9.13

[C_6H_5NH_3^+]=0.306M

[C_6H_5NH_2]=0.418M

pOH = ?

Putting values in equation 1, we get:

pOH=9.13+\log(\frac{0.306}{0.418})\\\\pOH=8.99

To calculate pH of the solution, we use the equation:

pH+pOH=14\\pH_{initial}=14-8.99=5.01

To calculate the molarity, we use the equation:

\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}

Moles hydrochloric acid solution = 0.124 mol

Volume of solution = 1 L

Putting values in above equation, we get:

\text{Molarity of HCl}=\frac{0.124}{1L}\\\\\text{Molarity of HCl}=0.124M

The chemical reaction for aniline and HCl follows the equation:

                   C_6H_5NH_2+HCl\rightarrow C_6H_5NH_3^++Cl^-

<u>Initial:</u>           0.418        0.124           0.306

<u>Final:</u>             0.294          -                0.430

Calculating the pOH by using using equation 1:

pK_b = negative logarithm of base dissociation constant of aniline  = 9.13

[C_6H_5NH_3^+]=0.430M

[C_6H_5NH_2]=0.294M

pOH = ?

Putting values in equation 1, we get:

pOH=9.13+\log(\frac{0.430}{0.294})\\\\pOH=9.29

To calculate pH of the solution, we use the equation:

pH+pOH=14\\pH_{final}=14-9.29=4.71

Calculating the pH change of the solution:

\Delta pH=pH_{initial}-pH_{final}\\\\\Delta pH=5.01-4.71=0.30

Hence, the pH change of the buffer is 0.30

You might be interested in
1. What is the correct order of the water cycle?
irga5000 [103]
C.
Evaporation
Condensation
Precipitation
3 0
2 years ago
Potential Energy vs Height
AleksandrR [38]

Answer:

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

Explanation:

5 0
2 years ago
Is 13.0 mv at 25 °c. calculate the concentration of the zn2 (aq) ion at the cathode?
Andrews [41]
Answer: 
 Zn =⇒ Zn+2(0.10) + 2e- (anode)
 Zn+2(?M) + 2e- === Zn(s) (cathode)
 
 Zn + Zn+2(?M) ===⇒ Zn+2(0.10) + Zn 
 E = E^o -0.0592 log Q; in this case E^o is zero. 
 E = - 0.0592 /n logQ where n is the number of electrons transferred, in this
case n = 2 
 23 mV x 1 volt/1000mv = 0.023 Volts 
 0.023 = -0.0592 / 2 log(0.10) / [Zn+2]
 0.023 = -0.0296 { log 0.10 – log [Zn+2] }
 0.023 = -0.0296{ -1 - log[Zn+2] }
 0.023 = +0.0296 + 0.0296log[Zn+2]
 -0.0066 = 0.0296log[Zn+2]
 -0.22= log[Zn+2]
 [Zn+2] = 10^-0.22 = 0.603 Molar

6 0
3 years ago
A spider has several eyes.
NikAS [45]
The main function is to help them see with all their eyes.
4 0
2 years ago
Read 2 more answers
How is a lithium atom (Li) different from a lithium ion (Li+)
UkoKoshka [18]

Answer:

(Li) has fewer electrons than (Li+)

3 0
3 years ago
Other questions:
  • You are working with a specific enzyme-catalyzed reaction in the lab. You are a very careful experimentalist, and as a result, a
    11·1 answer
  • What was the name of the start of something new in science?
    7·1 answer
  • A solution is made by dissolving 14.0 g of potassium chloride to a final volume of 78.9 mL solution. what is the weight/weight %
    8·2 answers
  • Under which conditions of temperature and pressure does oxygen gas behave least like an ideal gas?
    15·2 answers
  • The chart shows four environments and the kind of succession that would occur there.
    5·2 answers
  • if a mixture of 90 g of hydrogen sulfide and 70.5 g of chromium oxide are allowed to raeact what mass of water can be formed
    11·1 answer
  • What type of chemical bonds share electrons between atoms?
    8·1 answer
  • The correct mass of a block is 28.0 grams. A chemist measures the block
    11·1 answer
  • What is similarities ALL covalent,ionic,and metallic bonds have?
    15·1 answer
  • Americium-241 undergoes fission to produce three neutrons per fission event. if a neutron-absorbing material is mixed in with th
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!