Question

HgO is analysed by reaction with iodine and then titrating with an acid. The equivalent mass of HgO is:
${{H}_{2}}O+HgO+4{{I}^{-}}\to Hg{{I}_{4}}^{2-}+2O{{H}^{-}}$
A. M
B. $\dfrac{M}{2}$
C. $\dfrac{M}{4}$
D. $\dfrac{M}{3}$

Answer 1

Hint: Equivalent weight which is also known by the name gram equivalent is defined as the mass of one equivalent which can be simplify in a manner that mass of a given substance which will combine with or we can also explain it which will displace a fixed quantity of another substance.

Complete answer:
The equivalent weight of an element can be defined as the mass which combines with or displaces 1.008 gram of hydrogen or 8.0 grams of oxygen or 35.5 grams of chlorine. These values correspond to the atomic weight which is divided by its valency.
The equivalent mass of HgO known by the name mercury oxide can be examine by noticing the reaction and the reaction given is
${{H}_{2}}O+HgO+4{{I}^{-}}\to Hg{{I}_{4}}^{2-}+2O{{H}^{-}}$
We can see that in the given reaction one mole of mercury oxide gives two moles of hydroxide ions represented by the symbol $O{{H}^{-}}$, so the equivalent weight of Hgo can be calculated by $\dfrac{M}{2}$. If we consider one mole as M. Mole is generally represented by the symbol mol. It is generally described as the unit of measurement for amount of substance in SI where SI stands for International System of units. It is defined on the basis of Avogadro’s number.

Thus option B is the correct answer.

Note:
A mole of a substance or particle can be defined as containing exactly $6.02214076\times {{10}^{23}}$ particles which may be atoms, molecules or ions where $6.02214076\times {{10}^{23}}$ is known as the Avogadro’s number.