Question

Number of equivalents of a substance in its one mole is referred as:
A. Normality
B. Equivalent mass
C. Avogadro number
D. Valence number

Answer 1

Hint: The normality of the solution is defined as the gram equivalent weight of a solute per liter of the solution. The normality of the solution can be calculated by using its equivalent mass. The equivalent mass of a solution can be calculated by using the valence factor.

Complete step by step answer:
The normality of the solution is defined as the gram equivalent weight of a solute per litre of the solution. It can be written as follows,
\[Normality = \dfrac{{Equi.weight}}{{volume}}\]
Equivalent mass is the mass of one equivalent substance. It can be calculated by using the equation given below.
\[Eq.mass = \dfrac{{Molar.mass}}{{Valency}}\]
Avogadro number is the number of particles present in one mole of a substance. It is calculated to be \[6.023 \times {10^{23}}\]
Valence number is defined as the number of equivalents present in its mole of the solution.
Since it is known that, \[Eq.mass = \dfrac{{Molar.mass}}{{Valency}}\]
So, one equivalent is equal to the valence factor.
\[Equivalent = Moles \times valence.factor\]

Thus, option D is correct.

Note: Gram equivalent (one equivalent) is defined as the mass of the substance whereas equivalent mass is defined as the Equivalent mass is the mass of one equivalent of substance. Thus, equivalent mass can be obtained by dividing the molar mass of the substance by its valence number/factor whereas gram equivalent can be obtained by multiplying the moles of a substance with its valence number.