Question

1-6 please !

Lecture 19 At-home practice Which factor had the effect of decreasing the solubility (compared to all the other factors which increase solubility)? 1. A sample of PbSO4 solid has reached equilibrium in a beaker of water. If the ionic strength of the solution is then increased by adding LINO3 salt, what happens to the activity coefficients of the Pb2 and SO,2 ions? What happens to the solubility of the PbSO4? 2. Which of these four salts will increase in solubility if the solution is 3. acidified with a little HNO3(aq)? AgCl, PbF,2 CucO3, Nis Which of these four salts is more soluble in pure water than in a solution acidified with HCl(aq)? Fe3(PO)2, Pb(OH)2, PbCl2, BaF2 4. Lead compounds used as paint pigments are now prohibited because of lead toxicity. Which of these three compounds would give the most lead(I) ions at equilibrium, when added to the same quantity of water? (This comparison can be done conceptually because for all three compounds Ksp= x2) PbCrO, Kp 1.8x1014. PbSO, Kp 1.7x108. PbS, Ksp 5. = 2.5x10-27 sp More to think about: how could a chemist separate each salt from the others in a mixture of solid AgBr, NaNO3 6. and CuC,O4 salts?

Answer 1

This question is based upon solubility and I am here giving step by step explanation of each question.

1)

• The maximum amount of a substance which is dissolved in a given amount of solvent at a specific temperature is known as solubility.
• There are mainly two factors which affects the solubility one is temperature and other is pressure.
• Temperature affects the solubility of both solids and gases. In solids, the solubility generally increases with increasing temperature, But in gases, the solubility tends to decrease on increasing temperature.
• Hence, The temperature is that factor which decrease solubility in gases.

2) PbSO4 is sparingly soluble salt.

• When it is added in water it remains insoluble because of dipole strength of water.
• Lead Sulphate has strong crystals and the dipole strength of water is too weak to pull away ions from solution to become the salt soluble. But when we add lithium nitrate salt, the resulting mixture become soluble and the activity of ions is also become increase.

3) Silver chloride is insoluble in aqueous nitric acid because it does not react with it.

• PbF2 is soluble in aqueous nitric acid.
• CuCO3 is soluble and NiS is slightly soluble in aqueous nitric acid.
• Hence out of these four salts, the solubility of copper carbonate will increase due to some basic character.

4) fe3(po4)2 is insoluble in water.

• Lead(II) hydroxide, Pb(OH)₂ is not soluble or sparingly soluble base. It does not produce strongly basic solution by dissolved in distilled water.
• Except lead, silver, and mercury(I), the chlorides, bromides and iodides of all metals are soluble in water. PbCl2 is soluble in hot water.
• BaF2 is soluble in water.
• Hence BaF2 and PbCl2 is more soluble in water than other these two remaining salts.

5) PbS will give most lead ions in solution at equilibrium because of more solubility product.