Question

How do you calculate the relative formula mass $\left(M\right)$ of calcium carbonate? Relative atomic masses $C=12,O=16,Ca=40$?

Answer 1

An ionic compound formed between calcium ion $\left(C{a}^{2+}\right)$ and carbonate ion $\left(C{O}_3^{2-}\right)$.

After crossing over the number of the charges in $C{a}^{2+}$ and carbonate ion $C{O}_3^{2-}$ we'll get $C{a}_2(C{O}_3{)}_2$, which can be further simplified into $CaC{O}_3$.

And then, we multiply with its atomic mass and add them all up, like this,

Relative formula mass $CaC{O}_3=(1\times 40)+(1\times 12)+(3\times 16)=100$