Question

Consider these compounds:

A. MgCO3

B. PbF2

C. PbS

D. Ag2SO4

Complete the following statements by entering the letter corresponding to the correct compound.

Without doing any calculations it is possible to determine that silver hydroxide is more soluble than , and silver hydroxide is less soluble than .

It is not possible to determine whether silver hydroxide is more or less soluble than by simply comparing K_sp values.

A buffer solution is made that is 0.447 M in H₂S and 0.447 M in NaHS.
(1) If K_a for H₂S is 1.00×10^-7, what is the pH of the buffer solution?

(2) Write the net ionic equation for the reaction that occurs when 0.110 mol HBr is added to 1.00 L of the buffer solution.

Use H₃O⁺ instead of H⁺.

Please show your work and the ionic equation!!! Thanks !!!

Answer 1

AgOH   == > Ag+ + OH-

Ksp = 1.52 x 10-8

Complete the following statements by entering the letter corresponding to the correct compound.

Without doing any calculations it is possible to determine that silver hydroxide is more soluble than Ag₂SO₄ , because All sulfates are soluble except strontium sulfate and barium sulfate.

  and silver hydroxide is less soluble than PbS because All CO32- , sulfides, oxides and OH- are insoluble It is not possible to determine whether silver hydroxide is more or less soluble than by simply comparing K_sp values.

The solubility rules are as follows:

1. All Na+, K+, and NH4+ salts are soluble.
2. All nitrates, acetates and perchlorates are soluble.
3. All Ag+ , Pb+ and mercury(I) salts are insoluble.
4. All Cl-, Br- and I- are soluble.
5. All CO32- , sulfides, oxides and OH- are insoluble.
6. All SO42- are soluble except strontium sulfate and barium sulfate.

7. Fluorides are frequently insoluble. Examples: BaF₂, MgF₂ PbF₂.

8. Arsenic, antimony, bismuth, and lead sulfides are also insoluble and mainly sulfides of transition metals are highly insoluble. Thus, CdS, FeS, ZnS, Ag₂S are all insoluble.

A buffer solution is made that is 0.447 M in H₂S and 0.447 M in NaHS.
(1) If K_a for H₂S is 1.00×10^-7, what is the pH of the buffer solution?

K_a for H₂S is 1.00×10^-7

pKa = - log Ka

= - log 1.00×10^-7

= 7.00

First calculate the pH from Henderson –Hasselbalch equation as follows:

pH = pKa + log base/ acid

= 7.00 + log 0.447/0.447

= 7.00 + 0.0

= 7.00

(2) Write the net ionic equation for the reaction that occurs when 0.110 mol HBr is added to 1.00 L of the buffer solution.

0.447 M in NaHS = 0.447 M in Na + 0.447 HS-

0.110 mol HBr = 0.110 mol H3O+   + 0.110 mol Br-

0.447 HS- + 0.110 mol H3O+   = 0.110 mol H2S + 0.337 HS- + 0.110 mole H2O

The net ionic equation is

HS- + H3O+   = H2S + H2O