Question

The normality of ${{H}_{2}}S{{O}_{4}}$ having 50 milliequivalents in 2 liters is x N. The value of 1000x is:
A. 25
B. 30
C. 20
D. None of these

Answer 1

Hint: To solve this question you should have basic knowledge of the term Normality and equivalents weight. Normality is used in measuring the gram equivalent in the relation to the total volume of the solution. The units of normality are N or $eq{{L}^{-1}}$.

Complete answer:
Normality is defined as the number of gram or mole equivalents of solute present in one liter of a solution. It is denoted by the letter N. Equivalent weight is known as the mass of one equivalent, i.e. the mass of a substance taken under consideration which will combine with or displace a definite quantity of another substance in a chemical reaction. For an element the equivalent weight is nothing but the mass which combines with or displaces 1.008 gram of hydrogen or 8.0 gram of oxygen or 35.5 gram of chlorine. It is also known as gram equivalents.
$Normality=\dfrac{no.of gram equivalents}{volume of solution liter}$
As given in question we have to find the normality of ${{H}_{2}}S{{O}_{4}}$ having 50 milliequivalents in 2 liters is:
1000 milliequivalents of ${{H}_{2}}S{{O}_{4}}$ = 1-gram equivalent of ${{H}_{2}}S{{O}_{4}}$.
1 milliequivalents of ${{H}_{2}}S{{O}_{4}}$ = 11000 gram equivalent of ${{H}_{2}}S{{O}_{4}}$.
50 milliequivalents of ${{H}_{2}}S{{O}_{4}}$ = 50×11000 gram equivalent of ${{H}_{2}}S{{O}_{4}}$.
Hence, Normality = 50×11000×2 = 0.025 N
Hence, the value of x is 0.025.
The value of 1000x is = 0.025×1000 = 25

Hence, option A is correct.

Note:
To avoid calculation mistakes, convert all the quantities into SI units.
Normality is not a proper unit of concentration in some situations. It is an ambiguous measure and molarity and molality are better options for units.
A defined equivalence factor is essentially required by Normality.