Question

The oxide of metal have 20 % oxygen, the equivalent weight of oxide is:
a.) 32
b.) 40
c.) 48
d.) 52

Answer 1

Hint: To calculate the equivalent weight of the oxide first we need to find the molecular mass of oxygen and also the number of electrons gained or lost which is also known as n factor.

Complete Solution :
Equivalent weight of a substance is defined as the weight of a substance which combines with or which displaces one part by weight of hydrogen or eight parts by weight of oxygen or 35.5 part by weight of chlorine.
It is given in the question that the metal oxide has 20 percent oxygen which means that 100 gm of metal oxide contains 20 gm of oxygen. The equivalent weight of oxygen is 8.

The formulae which is used to calculate the equivalent weight is:
\[\dfrac{\text{mass of metal}}{\text{mass of oxygen}}=\dfrac{\text{equivalent weight of metal}}{\text{equivalent weight of oxygen}}\]

After substituting the given values in the above equation we get:
$\dfrac{80}{20}=\dfrac{E}{8}$
The equivalent weight of metal is 32 grams. Therefore, the equivalent weight of metal oxide is:
\[32+8=40\] gram
So, the correct answer is “Option C”.

Note: In the polymer chemistry, the equivalent weight of a reactive polymer is the mass of the polymer which has one equivalent of reactivity. It is widespread to indicate the reactivity polyol, isocyanate or epoxy thermostat resins which would undergo crosslinking reactions through those functional groups. The equivalent weight of a compound can be calculated by dividing the molar mass by the number of positive or negative electrical charges that result from the dissociation of the compounds.