9th Class Chemistry: Precipitation Titration

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the unit of Ksp?

Mol^2/L^2 (correct)

L/mol

Mol/L

Unitless

What is the molarity of oxalic acid solution used in the experiment?

0.01 M

1 M

10 M

0.1 M (correct)

What is the purpose of adding 2N H2SO4 in the experiment?

To decrease the pH of the solution (correct)

To maintain the pH of the solution

To increase the pH of the solution

To neutralize the oxalic acid

What is the mole ratio of oxalic acid to potassium permanganate?

2:1 Signup and view all the answers

What is the unit of solubility?

mg/L Signup and view all the answers

What is the purpose of heating the solution to 60-70°C in the experiment?

To increase the rate of reaction Signup and view all the answers

What is the concentration of potassium permanganate used in the experiment?

Not specified Signup and view all the answers

What is the purpose of repeating the titration three times?

To increase the accuracy of the result Signup and view all the answers

Why is nitric acid not used in the standardization of potassium permanganate?

Because it oxidizes potassium permanganate Signup and view all the answers

What is the mole ratio of iron to potassium permanganate?

1:5 Signup and view all the answers

What is the difference between a solution, suspension, and precipitate?

Solution is a homogeneous mixture, suspension is a heterogeneous mixture, and precipitate is a solid formed from a solution. Signup and view all the answers

What is the solubility product constant (Ksp) of a salt?

The product of the concentration of the ions that are present in a saturated solution of the salt. Signup and view all the answers

What does the Ksp value of a substance represent?

The level at which a solute dissolves in a solution. Signup and view all the answers

What is the Ksp value of CuBr if its molar solubility is 2.20x10-4 mol/L at 25°C?

4.0x10-8 mol2/L2 Signup and view all the answers

What is the Ksp value of Bi2S3?

1.1x10-73 mol/L3 Signup and view all the answers

Will NiCO3 precipitate in a solution that is 1.5 x 10–6 M in Ni2+ and 6.0 x 10–4 M in CO32–?

No, because Q < Ksp. Signup and view all the answers

Which forms first, solid AgI or solid AgCl?

AgI forms first. Signup and view all the answers

What is the formula for the Ksp of Pb3(PO4)2?

[Pb2+]3.[PO43-]2 Signup and view all the answers

What is the reaction quotient Q?

The product of the concentration of the ions that are present in a solution. Signup and view all the answers

What happens when the reaction quotient Q is less than the Ksp value?

No precipitate forms. Signup and view all the answers

Study Notes

Precipitation Titration

A solution is a homogeneous mixture of two or more substances, whereas a suspension is a heterogeneous mixture, and a precipitate is an insoluble solid that forms in a solution.

Solubility Product Constant (Ksp)

The solubility product constant (Ksp) is the product of the concentration of the ions that are present in a saturated solution of an ionic compound.
Ksp represents the level at which a solute dissolves in a solution; the more soluble a substance is, the higher the Ksp value it has.
For a salt AaBb, Ksp = [A+]a.[B-]b.

Examples of Ksp Calculations

For AgCl, Ksp = [Ag+].[Cl-].
For Pb3(PO4)2, Ksp = [Pb2+]3.[PO43-]2.

Calculating Ksp Values

Copper(I) bromide has a measured molar solubility of 2.20x10-4 mol/L at 25°C, so Ksp = 4.0x10-8 mol2/L2.
Bismuth sulfide (Bi2S3) has a solubility of 1.0x10-15 mol/L at 25°C, so Ksp = 1.1 x 10-73.

Precipitation Reaction

A solution is 1.5 x 10–6 M in Ni2+, and Na2CO3 is added to make the solution 6.0 x 10–4 M in CO32–. Since Q < Ksp, no precipitate will be formed.

Titration

Standardization of Potassium Permanganate

Transfer 10 ml oxalic acid solution (0.1 M) into a conical flask and add 20 ml, 2N H2SO4.
Heat the solution to 60-70°C and titrate slowly with potassium permanganate to the faint pink colour end-point.

Redox Titration

Standardization of potassium permanganate is used for the determination of iron.
Transfer 10 ml iron solution into a conical flask and add 20 ml, 2N H2SO4.
Titrate slowly with potassium permanganate to the faint pink colour end-point.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Learn about the difference between solution, suspension, and precipitate, and understand the concept of solubility product constant (Ksp) in chemistry.