Test: Boiling And Freezing Points Of Solutions


15 Questions MCQ Test Chemistry Class 12 | Test: Boiling And Freezing Points Of Solutions


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This mock test of Test: Boiling And Freezing Points Of Solutions for Class 12 helps you for every Class 12 entrance exam. This contains 15 Multiple Choice Questions for Class 12 Test: Boiling And Freezing Points Of Solutions (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Boiling And Freezing Points Of Solutions quiz give you a good mix of easy questions and tough questions. Class 12 students definitely take this Test: Boiling And Freezing Points Of Solutions exercise for a better result in the exam. You can find other Test: Boiling And Freezing Points Of Solutions extra questions, long questions & short questions for Class 12 on EduRev as well by searching above.
QUESTION: 1

Which one of the following is not a colligative property?

Solution:

Depression in freezing point is a colligative property but freezing point is not a colligative property.

QUESTION: 2

The molal elevation constant is the elevation in boiling point of

Solution:
QUESTION: 3

The colligative properties of a solution are

Solution:
QUESTION: 4

The information that is/are needed to determine the molar mass of an unknown solute is/are

Solution:
QUESTION: 5

What is the boiling point of a 3 molal aqueous solution if Kb is 0.512°C/m?

Solution:

QUESTION: 6

Which of the following is a colligative property?

Solution:

Colligative properties- The properties that depend upon the ratio of the number of solute molecules and total molecules not upon the nature of solute molecules named as colligative properties.

Example- Osmotic pressure, elevation of boiling point, depression in freezing point and relative lowering of vapour pressure.

QUESTION: 7

Beckmann thermometers are used to measure

Solution:
QUESTION: 8

A solution was made by dissolving 2 g of a solute in 100 g of acetone. The solution boiled at 56.95° C. The boiling point of pure acetone is 55.95° C, and the Kb =1.71°C/m. What is the molecular weight of the solute?

Solution:
QUESTION: 9

The molal elevation constant is the ratio of the elevation in B.P to:

Solution:
QUESTION: 10

Which of the two has lower freezing point, 2m NaCl or 5m NaCl aqueous solution?

Solution:
QUESTION: 11

If the vapour pressure of pure solvent A is 17.5 mm and lowering of vapour pressure of solution formed by adding a non-volatile electrolyte is 0.0175 mm then what is the relative lowering of vapour pressure?

Solution:
QUESTION: 12

Which of the following unit of concentration is independent of temperature?

Solution:

Molality (amount of moles per 1 kg of the solvent, mol/kg) and mole fraction (mol/mol) will remain constant since they are independent of volume of the solution which changes with temperature. Molarity i.e. amount of moles of a substance in 1 liter of a solution will change with volume of the solution so it will change with temperature.

QUESTION: 13

 Relative lowering of vapour pressure is directly proportional to

Solution:
QUESTION: 14

When common salt is dissolved in water:

Solution:

When a non-volatile solute is dissolved in a pure solvent, its vapour pressure is decreased. The difference in the boiling points of the solution and pure solvent is called elevation in boiling point.


 

The elevation in the boiling point of a solution of non-electrolyte is proportional to its molality and the equimolal solution of all the substances in the same solvent will show an equal elevation in boiling points. These are known as Raoult's laws of elevation of the boiling point.
 

So, the addition of salt will increases the boiling point of the solution.

QUESTION: 15

Camphor is used as solvent to determine the molecular mass of non-volatile solute by Rast method because for camphor

Solution:

The correct answer is “molal depression constant is high”.

Camphor is used for the determination of molecular masses of solute by Rast method because its molal depression constant is very high 40Kmolality-1 .

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