Question

Volume of $0.1N$${H_2}S{O_4}$ required to react completely with $5.6g$ of $CaO$ is:
$
  A)0.5L \\
  B)0.2L \\
  C)2L \\
  D)5L \\
 $

Answer 1

Hint: In this we use the law of gram equivalent. The fundamental basis of all titrations is the law of equivalence. According to which at the end point of titration, the volume of the two titrants reacted have the same number of equivalents or milli equivalents. Equivalent of solute $ = \dfrac{{normality}}{\text{volume of solute}}$

Complete answer:
Equivalent weight is the mass of one equivalent mass of a given substance which will combine with or displace a fixed quantity of another substance.
The number of gram equivalents of all the reactants will be equal and the same number of gram equivalents of each product will form. As the equivalent weights of all substances present in a reaction are determined by the same reference, their number of gram equivalents must be the same.
Equivalent weight $ = \dfrac{\text{Molecular Mass}}{{{n_f}}}$
Normality is defined as the number of equivalent weights of solute dissolved per liter of solution. Normality is used in place of molarity because often $1$ mole of acid does not neutralize 1 mole of base.
By using law of gram equivalent:
$
   \Rightarrow n \times {n_f} = n \times {n_f} \\
  ({H_2}S{O_4})(CaO) \\
$
$ \Rightarrow N \times V \times {n_f} = n \times {n_f}$
$ \Rightarrow 0.1 \times V \times 1 = 0.1 \times 2$
$ \Rightarrow V = \dfrac{{0.2}}{{0.1}} = 2L$
$ \Rightarrow 2L$
So, the correct answer is $C)2L$

Note:
In polymer chemistry, the equivalent weight of a reactive polymer is the mass of a polymer which has one equivalent of reactivity. It is widely used to indicate the reactivity of polyol, isocyanate, or epoxy thermoset resins which would undergo crosslinking reactions through those functional groups. It is particularly important for ion-exchange polymers: one equivalent of an ion-exchange polymer will exchange one mole of singly charged ions, but only half a mole of doubly charged ions.