Question

When an element forms an oxide in which oxygen is 20% of the oxide by mass, the equivalent mass of the element will be:

• A. 32
• B. 40
• C. 60
• D. 128

Answer 1

The correct option is A 32

Given,

Oxygen content of the oxide = 20%

Therefore, 100 g oxide contains 20 g oxygen and 80 g element.

Now,

Equivalent mass of element = (mass of element/ mass of oxygen) x 8

$=\frac{80}{20}\times 8$

$=32$

Hence, option $A$ is correct.