Elevation in Boiling Point

IMPORTANT

Elevation in Boiling Point: Overview

This topic covers concepts, such as, Elevation of Boiling Point, Molal Boiling Point Elevation Constant, Molal Boiling Point Elevation Constant Using Molar Heat of Vapourisation & Molar Heat of Vapourisation etc.

Important Questions on Elevation in Boiling Point

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)

EASY
IMPORTANT

The energy is required to vaporize a liquid, molar enthalpy of vaporization has a _____ sign.

EASY
IMPORTANT

The energy is _____ by the system to get the molecules into the gas state.

EASY
IMPORTANT

What is the unit of the molar heat of vaporization?

EASY
IMPORTANT

Express the formula for the molar heat of vaporization.

EASY
IMPORTANT

Discuss the molar heat of vaporization.

MEDIUM
IMPORTANT

18 g of glucose C6H12O6 dissolved in 1 kg of water is heated to boiling. The boiling point (in K) measured at 1 atm pressure is closest to [Ebullioscopic constant, Kb for water is 0.52 K kg mol-1. Consider absolute zero to be -273.15°C]

EASY
IMPORTANT

The molal boiling point elevation constant depends upon

MEDIUM
IMPORTANT

A solution of 122 g of benzoic-acid in 1000 g of benzene shows a boiling point elevation of 1.4°. If the solute is dimerized to an extent of 80%, the boiling point of pure benzene will be_________  (Molar enthalpy of vaporization of benzene =7.8kcal.mol-1 )

EASY
IMPORTANT

The elevation in boiling point of a solution of 10 g of a binary electrolyte (of molecular mass 100) in 100 g of water is ΔTb. Then the value of Kb for water is

EASY
IMPORTANT

Molal elevation constant is the elevation in boiling point produced by

EASY
IMPORTANT

The boiling point (in C) of 0.1 molal aqueous solution of CuSO4.5H2O at 1 bar is closest to: [Given: Ebullioscopic (molal boiling point elevation) constant of water, Kb=0.512 K kgmol-1

EASY
IMPORTANT

The molal elevation constant for water is 0.52. What will be the boiling point of 2 molar sucrose solution at 1 atm pressure? (Assume that the boiling point of pure water is 100 )

MEDIUM
IMPORTANT

Which of the following are correct for the elevation of boiling point (Tb):

EASY
IMPORTANT

The boiling point of 0.001 M aqueous solutions of NaCl, Na2SO4, K3PO4 and CH3COOH should follows the order.

MEDIUM
IMPORTANT

Latent heat of vaporization for a liquid solvent is 500 cal g-1. Let the boiling point be Tb K. Find the value of Kb of the solvent in K kg mol-1

HARD
IMPORTANT

A protein has been isolated as sodium salt with their molecular formula NaxP (this notation means that xNa+ ions are associated with a negatively charged protein P-x). A solution of this salt was prepared by dissolving 0.25g of this sodium salt of protein in 10g of water and ebullioscopic analysis revealed that solution boils at temperature 6.78 x 10-3 oC higher than the normal boiling point of pure water. Kb of water is 0.52 k kg mol-1. Also elemental analysis revealed that the salt contain 1% sodium metal by weight.

Determine molecular weight of acidic form of protein :

HARD
IMPORTANT

For next two question please follow the same

A protein has been isolated as sodium salt with their molecular formula NaxP (this notation means that xNa+ ions are associated with a negatively charged protein P-x). A solution of this salt was prepared by dissolving 0.25g of this sodium salt of protein in 10g of water and ebullioscopic analysis revealed that solution boils at temperature 6.78 x 10-3 oC higher than the normal boiling point of pure water. Kb of water is 0.52 k kg mol-1. Also elemental analysis revealed that the salt contain 1% sodium metal by weight.

Determine molecular weight of sodium salt of protein.

EASY
IMPORTANT

The molal elevation constant is the ratio of the elevation in boiling point to: