Elevation in Boiling Point of the Solvent

IMPORTANT

Elevation in Boiling Point of the Solvent: Overview

This Topic covers sub-topics such as Elevation of Boiling Point, Molal Boiling Point Elevation Constant, Molal Boiling Point Elevation Constant Using Molar Heat of Vapourisation and, Molecular Mass of a Solute through Elevation of Boiling Point

Important Questions on Elevation in Boiling Point of the Solvent

MEDIUM
IMPORTANT

A solution containing 8 g of a substance in 100 g of diethyl ether boils at 36.86°C,  whereas, pure ether boils at 35.60°C.

The molecular mass of the solute would be: (for etherKb=2.05Kkgmol1)

HARD
IMPORTANT

The boiling point elevation of 0.30 g acetic acid in 100 g benzene is 0.0633 K. From this data, find the molar mass of acetic acid. (For benzene, Kb=2.53 K ​kg mol-1)

MEDIUM
IMPORTANT

If an equimolar solution of CaCl2, and AlCl3 in water have boiling point of T1 and T2 respectively then

HARD
IMPORTANT

Define elevation in boiling point. How can you calculate the molecular mass of a non-volatile solute with it ?

HARD
IMPORTANT

If the boiling points of two solvents X and Y (having same molecular weights) are in the ratio 2: 1 and their enthalpy of vaporizations are in the ratio 1: 2, then the boiling point elevation constant of X is m times the boiling point elevation constant of Y. The value of m is (nearest integer).

HARD
IMPORTANT

Sea water contains 29.25%NaCl and 19%MgCl2 by weight of solution. The normal boiling point of the sea water is C (Nearest integer) Assume 100% ionization for both NaCl and MgCl2 Given: KbH2O=0.52 K kg mol-1 Molar mass of NaCl and MgCl2 is 58.5 and 95 g mol-1 respectively.

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60 g of a non-volatile solid AB(having crystals like NaCl) is dissolved in 0.50 kg water. The normal boiling point of solution is found to be 102.08°C. The molal elevation of water is 0.52 K-kg mol1. The density of solid AB is 6.25 g/cm3 and the edge-length of unit cell is 400 pm. The effective number of atoms per unit cell is (Use Avogadro's number =6×1023)

HARD
IMPORTANT

Calculate the elevation in boiling point of an aqueous solution of 0.1 molal monobasic acid, which undergoes 25% ionization is (Kb(H2O)=0.52 Kmolal-1)

MEDIUM
IMPORTANT

2g of non-electrolyte solute dissolved in 200g of water shows an elevation of boiling point of 0.026oC. Kb of water is 0.52K. mole-1 Kg then the molecular weight of solute is x×100. What is the value of 'x'?

MEDIUM
IMPORTANT

Calculate the molal elevation boiling point constant of a solution containing 1.0 g of urea (M=60) in 75 g water and boils at 100.114C.

MEDIUM
IMPORTANT

The molal elevation constant for water is 0.56 K kg mol1. Calculate the boiling point of solution made by dissolving 6.0 g of urea (NH2CONH2) in 200 g of water.

EASY
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The rise in boiling point of a solution containing 1.8 g of glucose in 100 g of solvent is 0.1°C. The molal elevation constant of the liquid is

EASY
IMPORTANT

The aqueous solution that shows the maximum boiling point elevation is [Assume identical conditions]

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IMPORTANT

Calculate the boiling point of solution when 4 g of MgSO4 M=120 g mol-1 was dissolved in 100 g of water, assuming MgSO4 undergoes complete ionization. (kb for water=0.52 K Kg mol-1)

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6 g of urea and 1 g of glucose are dissolved 300 g of water find the boiling point of solutions and pure water boiling point is 100Ckb for water is 0.52 kkg/mol.

MEDIUM
IMPORTANT

A student observed that the boiling of the water containing 10 g/l of NaCl was 101.5C. If more water is added to the solution, will its boiling point increase or decrease? Give reason.

HARD
IMPORTANT

1L of aq. Solution of urea having density = 1.060 gm/mL is found to have ΔTb = 0.5°C, if temperature of this solution increase to 101.5°C then calculate amount of water which must have gone into vapour state up to this point. Given Kb= 0.5 Kkgmol-1 for water

MEDIUM
IMPORTANT

Which of the following aqueous solutions should have the minimum boiling point?

EASY
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What will happen to the boiling point of a solution if the weight of the solute dissolved is doubled but the weight of solvent taken is halved?

EASY
IMPORTANT

Which solution has maximum boiling point?