Question

The formula of phosphate of an element R is RPO, then the formulae of its hydroxide and sulphide will be​

Answer 1

Explanation:

To solve this kind of questions, we need to know the oxidation states of different ions.

So we consider the oxidation state of the ion ‘R’ to be x

And we should be knowing that the oxidation state of a phospate ion is 3-.

The compound is made up of 2 ions basically:

Rx and PO3−4

Now arrange these numbers and variables to form an equation

x+(−3)=0

x=3

Therefore the oxidation state of ion ‘R’ is 3+

The formula of hydroxide of R will be:

Cross multiply the valencies.

R=3

OH=1

R(OH)3

The formula of the sulfide of R will be as follows:

R=3

S=2

R2S3

Answer 2

From the given data we know that X belongs to oxygen family. So, X possesses valency of 2. When X reacts with hydrogen it forms H

2

X.

Thus, the molecular formula of the compound is H

2

X.