Question

An element 'x' has a valency 3. Write the formula of its oxide.

Answer 1

Compound 'X' has valency 3 and 'O' has valency 2 . L.C.M of 3 & 2 is 6 .
For X = 3 * 2 = 6
For O = 2 * 3 = 6
Therefore $X_{2}O_{3}$ is the formula of oxide of 'X'

Answer 2

As per the given, an element with a valency of 3, and its formula for its oxide is $\bold{\mathrm{x}_{2} \mathrm{O}_{3}}$.

Explanation:

An element with valency 3 can be written as X=+2  

It is given that it forms an oxide which means it will react with oxygen which has a valency of 2. The “valency of oxygen” is written as O=-2.

We now use the criss-cross method of finding the valency of the oxide.

So we get $\mathrm{x}_{2} \mathrm{O}_{3}$, Which is the required formula of oxide.