Question

The atomic weight of metal (M) is 27 and its equivalent weight is 9. The formula of its chloride will be :
A.${\text{MCl}}$
B.${\text{MC}}{{\text{l}}_2}$
C.${\text{MC}}{{\text{l}}_4}$
D.None

Answer 1

Equivalent mass of {\text{AxBy}}$$$$ = equivalent mass of {\text{A}}$$$$ + equivalent mass of ${\text{B}}$.
Equivalent mass of chloride :
Element $+$ chlorine $\to$ chloride
Equivalent mass of chloride $=$ equivalent mass of element $+$ equivalent mass of chlorine

Complete step by step answer:
Given, atomic weight = 27
Equivalent weight= 9
Now we assume that the formula of its chloride is${\text{MC}}{{\text{l}}_{\text{x}}}$
${\text{x = }}\dfrac{{{\text{atomic weight}}}}{{{\text{equivalent weight}}}}$
$= \dfrac{{27}}{9} = 3$
So we see that,${\text{MC}}{{\text{l}}_{\text{3}}}$ is the formula for its chloride.

Therefore the correct option is (D).

Additional information:
-The molecular mass is the mass of a given molecule where different molecules have the same compound but they have different molecular masses due to different isotopes of an atom. The molecular mass and relative molecular mass are different but related to the molar mass. The molar mass is defined as the mass of a given substance which is divided by the substance amount and its unit is g/mol. Usually the molar mass is a more appropriate figure when dealing with macroscopic quantities of a substance.
Equivalent weight of element${\text{ = }}\dfrac{{{\text{molecular weight}}}}{{{\text{valency of element}}}}$
-Normality is defined as the number of gram equivalents of a solute contained in ${\text{1}}\,{\text{L}}$ of a solution. Means a solution which contains ${\text{1}}\,{\text{gm}}$ equivalent of the solute per liter of the solution is called normal solution. It is represented as ${\text{1}}\,{\text{N}}$.
-Gram equivalent is the weight of substance in gram numerically equivalents to its equivalent weight.
-The equivalent weight of an acid that weighs it which contains ${\text{1}}{\text{.008gm}}$of replaceable hydrogen.
-The equivalent weight of a base is that weight of it which contains one replaceable hydroxyl group .
For example, ${\text{HCl}}$ and ${\text{NaOH}}$ have only replaceable ${{\text{H}}^{\text{ + }}}$ and ${\text{O}}{{\text{H}}^{\text{ - }}}$ hence the equivalent weight of them are equal to their molecular weights.

Note:
The equivalent weight of a polymer is the mass of the polymer which is having one equivalent of reactivity. Which is used to indicate the reactivity of resins which would undergo cross link reactions through the functional groups.