Question

what is the oxidation number of ca in caso4

Answer 1

+2is the oxidation number of ca in caso4
caso4
x+(-2)=0
x=2
here consider oxidation number of ca as (x)

Answer 2

The oxidation number of Calcium (Ca) in Calcium Sulphate $\bold{\left(\mathrm{CaSO}_{4}\right)}$ can be determined as follows:

Let the oxidation number of Calcium (Ca) be +x

We know oxidation state of Sulphate $\left(\mathrm{SO}_{4}\right)$ ion is -2.

Net charge on Calcium Sulphate $\left(\mathrm{CaSO}_{4}\right)$ is zero (0)

Therefore, +x + -2 = 0

x = 2

Therefore, the oxidation state of Ca in Calcium Sulphate $\left(\mathrm{CaSO}_{4}\right)$ is determined as +2.  

In the redox reaction, the oxygen will always have +2 oxidation states.

Calcium Sulphate is used in construction works as Plaster of Paris.