Question

An unknown element forms an oxide. What will be the equivalent weight of the element if the oxygen content is 20% by weight

• A. 14
• B. 32
• C. 2
• D. 54

Answer 1

Answer: (B)

Equivalent weight (also known as gram equivalent is the mass of one equivalent, that is the mass of a given substance which will combine with or displace a fixed quantity of another substance. The equivalent weight of an element is the mass which combines with or displaces 1.008 gram of hydrogen or 8.0 grams of oxygen or 35.5 grams of chlorine.
Let the oxide of unknown element be MO.
Given that oxygen content is 20% by weight.
Then, Eq. weight of unknown element (M) $=\frac{80}{20}\times 8$ $g$
Equivalent weight of unknown element (M) $=32$ $g$ .