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

Let us assume that the total amount of oxide be $100$

Therefore, Mass of Oxygen $=20$ (because it is $20$% given)

Then, mass of the element would be $=100-20=80$

Now, equivalent mass of element $=\frac{Massofelement}{MassofOxygen}\times 8$

$=\frac{80}{20}\times 8=32$