Question

Calculate the quotient [H3PO4]/[H2PO4] in 0.05 M K2HPO4. K1= 7.11x10^-3, K2= 6.32x10^-8, K3=4.17x10^-3

Answer #1

HPO42- ---------------> H+ + PO43-

0.05 0 0

0.05 - x x x

ka3 = x^2 / 0.05 - x

4.17 x 10^-13 = x^2 / 0.05 - x

x = 1.44 x 10^-7

[H+] = 1.44 x 10^-7 M

H3PO4 -------------> H+ + H2PO4-

Ka1 = [H+][H2PO4-] / [H3PO4]

7.11 x 10^-3 = [H2PO4-] x 1.44 x 10^-7 / [H3PO4]

[H2PO4-] / [H3PO4] = 49241.6

**[H3PO4] / [H2PO4-] = 2.03 x 10^-5**

(a) Calculate the quotient [H3PO4]/[H2PO4− ]
in 0.0463 M KH2PO4. (Assume
Kw = 1.01 ✕ 10−14, Ka1 = 7.11 ✕ 10−3, Ka2 = 6.34 ✕ 10−8, and Ka3 = 4.22 ✕ 10−13.)

Question 2. Calculate the F-obtained value using the
below table
K1
K2
K3
K4
X
X-squared
X
X-squared
X
X-squared
X
X-squared
6
8
12
18
6
10
12
18
8
10
16
22
8
12
16
22
12
18
Total
Total
Total
Total
Total
Total
Total
Total
X̅1=
X̅2=
X̅3=
X̅4=

Calculate the pH and the equilibrium concentrations of H2PO4-,
HPO42- and PO43- in a 0.0353 M aqueous phosphoric acid solution.
For H3PO4, Ka1 = 7.5×10-3, Ka2 = 6.2×10-8, and Ka3 = 3.6×10-13
pH = ?
[H2PO4-] = ?M
[HPO42-] = ?M
[PO43-] = ?M

What is the [H2PO4-] of a
solution labeled "0.10 M Phosphoric Acid
(H3PO4)"?
[Ka1 = 7.1x10-3; Ka2 =
6.3x10-8; Ka3 = 4.2x10-13]
A. 4.2x10-13 M
B. 2.7x10-2 M
C. 7.1x10-3 M
D. 1.6x10-9 M
E. 1.6x10-16 M

The formal composition of an aqueous solution is 0.12 M K2HPO4 +
0.08 KH2PO4. The pKa's for triprotic phosphoric acid are 2.12,
7.21, and 12.32. Show the three equilibriums in solution and
calculate the pH of the solution. Find concentrations of K+, H3PO4,
H2PO4^-, HPO4^2-, PO4^3-, H+, and OH^- in the mixture.

Given the following Ka values:
H3PO4 <-->
H2PO4- + H+, Ka =
7.11*10-3
H2PO4- <-->
HPO42- + H+, Ka =
6.34*10-8
HPO42- <-->
PO43- + H+, Ka =
4.22*10-13,
a) please calculate the pH of the solution at the first
equivalence point for the above titration.
b) In the same titration as described above, what's the pH of
the solution after 15.00 mL of NaOH was added?

Determine the pH of a 0.0520 M solution of the following salts.
A table of pertinent K values is found to the right. a) NaHCO3 b)
NaH2PO4
acid
formula
K1
k2
k3
arsenic acid
H3AsO4
5.8e-3
1.1e-7
3.2e-12
carbonic acid
H2CO3
4.45e-7
4.69e-11
hydrogen sulfide
H2S
9.6e-8
1.3e-14
phosphoric acid
H3PO4
7.11e-3
6.32e-8
4.5e-13

Part A:
Given the two reactions
H2S⇌HS−+H+, K1 = 9.51×10−8,
and
HS−⇌S2−+H+, K2 =
1.33×10−19,
what is the equilibrium constant Kfinal for the
following reaction?
S2−+2H+⇌H2S
Part B:
Given the two reactions
PbCl2⇌Pb2++2Cl−, K3 =
1.83×10−10, and
AgCl⇌Ag++Cl−, K4 =
1.20×10−4,
what is the equilibrium constant Kfinal for the
following reaction?
PbCl2+2Ag+⇌2AgCl+Pb2+

Calculate the concentrations of all species in a 0.180-M
solution of H2X if K1 = 5.01E-05 and
K2 = 2.82E-08
[H2X] =
M
[H3O1+] =
M
[HX1-] =
M
[X2-] =
M

Calculate the concentrations of all species in a 0.230-M
solution of H2X if K1 = 3.16E-05 and
K2 = 2.40E-08
[H2X] = .230
M
[H3O1+] =
M
[HX1-] =
M
[X2-] =
M

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 1 minute ago

asked 1 minute ago

asked 25 minutes ago

asked 27 minutes ago

asked 28 minutes ago

asked 32 minutes ago

asked 35 minutes ago

asked 36 minutes ago

asked 37 minutes ago

asked 38 minutes ago

asked 46 minutes ago

asked 48 minutes ago