Question

1. Which of the following terms areunitless?
O Molality and normality
Molarity and molality
OMole fraction and mass percent
Omolarity and normality​

Answer 1

ANSWER

Molarity is given by M=

V

solution

n

solute

here V is the volume of the solution which is temperature dependent.

Molality is given by m=

W

solvent

n

solute

W

solvent

is the mass of solvent which is independent of temperature.

Normality is given by N=

V

solution

n

equivalent solute

Here, it is dependent on volume which is temperature dependent.

Mole fraction is dependent on the amount of substance which is temperature independent.

Therefore, Molality and mole fraction are temperature independent.

How satisfied are you with the answer

Answer 2

Unit less terms are -

Mole fraction and mass percent.

Molarity is given by the formula - number of moles/volume of solution in litres.

Hence, unit is - mol/litre also represented as "M".

Molality is given by the formula - number of moles/mass of solvent in kilogram.

Hence, unit is - mol/kg.

Normality is given by the formula - number of gram equivalents/volume of solution in litres.

Hence, unit is - eq/litre or "N".

Mole fraction is calculated by the formula - number of moles of solute/total number of moles.

Since both are same units, they will be cancelled. Hence, it is unit less.

Mass percentage is calculated by the formula - (mass of solute or solvent/mass of solution)*100

Here again both are same units therefore will be cancelled. Hence, it is unit less.