Question

Calculate the molar solubility of CaF2 in a solution buffered to a pH of 8.250

Answer #1

1) The chemical equation:

CaF_{2} ⇌ Ca^{2+} + 2F¯

2) The K_{sp} expression:

K_{sp} = [Ca^{2+}] [F¯]^{2}

3) Use the pH to get the pOH:

14.00 - 8.250 = 5.75

4) Use the pOH to get the [OH¯]:

[OH¯] = 10¯^{pOH} = 10¯^{5.75} = 1.7782 x
10¯^{6} M

5) From the chemical equation, we note that the
[Ca^{2+}] is half the value of the [F¯], therefore:

[Ca^{2+}] = 1.7782 x 10¯^{6} M divided by 2 =
8.8913 x 10¯^{7} M

6) We now have the necessary values to put into the
K_{sp} expression:

K_{sp} = (8.8913 x 10¯^{7}) (1.7782 x
10¯^{6})^{2}

K_{sp} =(8.8913 x 10¯^{7}) (3.1619 x
10¯^{12})

K_{sp} =28.1142 x 10¯^{19}

CaF2 = Ca++ + 2 F-

Let "X" equal the molar solubility of CaF2. Then:

[X][2X]^2 = 28.1142 x 10¯^{19}

4 X^3 = 28.1142 x 10¯^{19}

X^3 = 7.02X 10^-19

X = (7.02X 10^-19)^-3

X= **8.8874 x 10^-7** is the the molar solubility
of CaF2.

X = 2.04 X10^-4

So the molar solubility of CaF2 = 2.04 X 10^4 M

Calculate the molar solubility of calcium hydroxide in a
solution buffered at each of the following
pH's.
1) pH=3
2) pH=10

Determine the molar solubility (S) of Ag2CO3 in a buffered
solution with a pH of 5.868 using the systematic treatment of
equilibrium. Ksp(Ag2CO3) = 8.46 × 10–12; Ka1(H2CO3) = 4.45 × 10–7;
Ka2(H2CO3) = 4.69 × 10–11.

Determine the molar solubility (S) of Ag2CO3 in a buffered
solution with a pH of 4.616 using the systematic treatment of
equilibrium. Ksp(Ag2CO3) = 8.46 × 10–12; Ka1(H2CO3) = 4.45 × 10–7;
Ka2(H2CO3) = 4.69 × 10–11.

Determine the molar solubility (S) of Ag2CO3 in a buffered
solution with a pH of 4.271 using the systematic treatment of
equilibrium. Ksp(Ag2CO3) = 8.46 × 10–12; Ka1(H2CO3) = 4.45 × 10–7;
Ka2(H2CO3) = 4.69 × 10–11.

Calcium fluoride, CaF2, has a molar solubility of 2.1 x 10^–4
mol L^–1 at pH = 7.00. By what factor does its molar solubility
increase in a solution with pH = 3.00? The pKa of HF is 3.17. The
answer is 1.83

Calculate the molar solubility of Mg(OH)2 in a
solution that is basic with a pH of 12.68.
Ksp = [Mg2+][OH–]2 =
5.6 × 10–12

Calculate the solubility of Cobalt (II) Hydroxide in a solution
which has been buffered to have a pH of 10.00. Cobalt (II)
Hydroxide has Ksp = 5.29 x 10-15

What is the solubility of silver oxide, Ag2O, in a solution
buffered at pH 10.5? The equilibrium is Ag2O(s) +H2O(l) 2Ag+(aq) +
2OH-(aq); Kc = 2.0E-8.
________ g/L

What is the solubility of
Ca3(PO4)2 (s) in mg/L, in
a solution buffered at pH 7.2 using a phosphate buffer such that
TOTPO4 = 10-2M?

Calculate the molar solubility of Fe(OH)2 in a buffer
solution where the pH has been fixed at the indicated values.
Ksp = 7.9 x 10-16.
(a) pH 8.0
(b) pH 11.0
(c) pH 13.6
HopHelpCh17N6

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 4 minutes ago

asked 5 minutes ago

asked 9 minutes ago

asked 9 minutes ago

asked 14 minutes ago

asked 19 minutes ago

asked 39 minutes ago

asked 58 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago