pH calculation
a) 0.00 ml HNO3 added
[aziridine] = 0.0750 M
aziridine + H2O <==> aziridineH+ + OH-
let x amount has reacted
Kb = [aziridineH+][OH-]/[aziridine]
pKa = 8.04
pKb = 14 - pKa = 5.96
pKb = -log[Kb] = 5.96
Kb = 1.1 x 10^-6
1.1 x 10^-6 = x^2/0.0750
x = [OH-] = 2.87 x 10^-4 M
pOH = -log[OH-] = 3.54
pH = 14 - pOH = 10.46
b) 6.81 ml HNO3 added
initial moles [aziridine] = 0.0750 M x 60 ml = 4.5 mmol
moles HNO3 added = 0.0676 M x 6.81 ml = 0.46 mmol
[aziridineH+] formed = 0.46 mmol/66.81 ml = 0.007 M [acid]
[aziridine] remained = (4.5 - 0.46) mmol/66.81 ml = 0.060 M [base]
pH = pKa + log(base/acid)
= 8.04 + log(0.060/0.007)
= 8.98
c) volume of HNO3 equal to half the equivalence point volume
initial moles [aziridine] = 0.0750 M x 60 ml = 4.5 mmol
Volume of HNO3 added = 4.5 mmol/2 x 0.0676 M = 33.28 ml
moles HNO3 added = 0.0676 M x 33.28 ml = 2.25 mmol
[aziridineH+] formed = 2.25 mmol/93.28 ml = 0.024 M [acid]
[aziridine] remained = (4.5 - 2.25) mmol/93.28 ml = 0.024 M [base]
pH = pKa + log(base/acid)
= 8.04 + log(0.024/0.024)
= 8.04
at this point half of aziridine has reacted with added HNO3 to form aziridineH+
So,
[aziridineH+] formed = [aziridine] remained in solution
pH = pKa = 8.04
d) 62.6 ml HNO3 added
initial moles [aziridine] = 0.0750 M x 60 ml = 4.5 mmol
moles HNO3 added = 0.0676 M x 62.6 ml = 4.232 mmol
[aziridineH+] formed = 4.232 mmol/122.6 ml = 0.0345 M [acid]
[aziridine] remained = (4.5 - 4.232) mmol/122.6 ml = 0.0022 M [base]
pH = pKa + log(base/acid)
= 8.04 + log(0.0022/0.0345)
= 6.84
e) Volume of HNO3 equal to the equivalence point
initial moles [aziridine] = 0.0750 M x 60 ml = 4.5 mmol
Volume of HNO3 added to reach equivalence point = 4.5 mmol/0.0676 M = 66.57 ml
moles HNO3 added = 0.0676 M x 33.28 ml = 4.5 mmol
all of aziridine is neutralized
[aziridineH+] formed = 4.5 mmol/126.57 ml = 0.0355 M [acid]
aziridineH+ + H2O <==> aziridine + H3O+
let x amount has reacted
Ka = [aziridine][H3O+]/[aziridineH+]
pKa = -log[Ka] = 8.04
9.12 x 10^-9 = x^2/0.0355
x = [H3O+] = 1.80 x 10^-5 M
pH = -log[H3O+] = 4.745
f) 70.5 ml HNO3 added
initial moles [aziridine] = 0.0750 M x 60 ml = 4.5 mmol
moles HNO3 added = 0.0676 M x 70.5 ml = 4.766 mmol
excess [HNO3] = [H+] present
= (4.766 - 4.5) mmol/130.5 ml
= 2.04 x 10^-3 M
pH = -log[H+] = 2.69
Calculate the pH of the solution after the addition of the following amounts of 0.0676 M...
Calculate the pH of the solution after the addition of the following amounts of 0.0601 M HNO_3 to a 60.0 mL solution of 0.0750 M aziridine. The pK_a of aziridinium is 8.04. a) 0.00 mL of HNO_3 d) 9.53 mL of HNO_3 c) Volume of HNO_3 equal to the equivalence point volume d) 70.4 mL of HNO_3 e) Volume of HNO_3 equal to the equivalence point f) 77.9 mL of HNO_3
Calculate the pH of the solution after the addition of the following amounts of 0.0525 M HNO_3 to a 80.0 mL solution of 0.0750 M aziridine. The pK_a of aziridinium is 8.04. a) 0.00 mL of HNO_3 pH = 12.9 b) 6.44 mL of HNO_3 pH = 9.26 c) Volume of HNO_3 equal to half the equivalence point volume pH = 8.04 d) 111 mL of NHO_3 pH = 6.57 e) Volume of HNO_3 equal to the equivalence point pH...
Calculate the pH of the solution after the addition of the following amounts of 0.0577 M HNO_3 to a 80.0 mL solution of 0.0750 M aziridine. The pK_a of aziridinium is 8.04. a) 0.00 mL of HNO_3 pH b) 8.45 mL of HNO_3 PH = c) Volume of HNO_3 equal to half the equivalence point volume pH = d) 1.00 times 10^2 mL of HNO_3 pH = e) Volume of HNO_3 equal to the equivalence point pH = f) 109...
I really need help with c-f please Calculate the pH of the solution after the addition of the following amounts of 0.0576 M HNO_3 to a 50.0 mL solution of 0.0750 M aziridine. The pK_a of aziridinium is 8.04. a) 0.00 mL of HNO_3 pH = b) 9.00 mL of HNO_3 pH = c) Volume of HNO_3 equal to half the equivalence point volume pH = d) 61.9 mL of HNO_3 pH = e) Volume of HNO_3 equal to the...
Calculate the pH of the solution after the addition of each of the given amounts of 0.0503 M HNO3 0.0503 M HNO3 to a 60.0 mL solution of 0.0750 M 0.0750 M aziridine. The pKa of aziridinium is 8.04 What is the pH of the solution after the addition of 0.00 mL HNO3? 0.00 mL HNO3? pH= What is the pH of the solution after the addition of 8.69 mL HNO3? 8.69 mL HNO3? pH= What is the pH of...
Calculate the pH of the solution after the addition of each of the given amounts of 0.0541 M HNO, to a 60.0 mL solution of 0.0750 M aziridine. The pK, of aziridinium is 8.04. What is the pH of the solution after the addition of 0.00 mL HNO,? pH = What is the pH of the solution after the addition of 8.32 mL HNO,? pH = What is the pH of the solution after the addition of a volume of...
Calculate the pH of the solution after the addition of each of the given amounts of 0.0557 M HNO, to a 60.0 mL solution of 0.0750 M aziridine. The pK, of aziridinium is 8.04. What is the pH of the solution after the addition of 0.00 mL HNO,? pH = What is the pH of the solution after the addition of 5.11 mL HNO,? pH = What is the pH of the solution after the addition of a volume of...
Calculate the pH of the solution after the addition of each of the given amounts of 0.0504 M HNO, to a 60.0 mL solution of 0.0750 M aziridine. The pK, of aziridinium is 8.04. What is the pH of the solution after the addition of 0.00 mL HNO,? pH = What is the pH of the solution after the addition of 8.55 mL HNO,? pH = What is the pH of the solution after the addition of a volume of...
Calculate the pH of the solution after the addition of each of the given amounts of 0.0576 M HNO2 to a 50.0 mL solution of 0.0750 M aziridine. The pKa of aziridinium is 8.04 What is the pH of the solution after the addition of pH 0.00 mL HNO,? What is the pH of the solution after the addition of pH 7.41 mL HNO? What is the pH of the solution after the addition of a volume pH of HNO...
Calculate the pH of the solution after the addition of each of the given amounts of 0.0655 M HNO, to a 50.0 mL solution of 0.0750 M aziridine. The pK, of aziridinium is 8.04. What is the pH of the solution after the addition of 0.00 mL HNO,? pH = What is the pH of the solution after the addition of 7.78 mL HNO,? What is the pH of the solution after the addition of a volume of HNO, equal...