Question

What is the molar mass of $F{{e}^{3+}}$. How many ions does it have and what is the mass of the ion one mole of compound?

Answer 1

The mass of single electron is approximately $2000$ times smaller than those of a proton and a neutron, So you can safely assume that the addition of electrons in the can of cation has little to no impact on moles mass.

Complete step by step answer:
$F{{e}^{3+}}\to$ iron $\left( 3+ \right)$ is an iron cation and a monatomic friction. It has a role as a human metabolite. The only difference between an $Fe$ atom and an $F{{e}^{3+}}$ ion is three electrons.
$\to$The electrons have so little mass compared to the rest of the atom that their masses. The molar mass of $Fe$ and $F{{e}^{3+}}$ are the same $55.845g/mol.$
$\to$ Moreover, $1$mole of $F{{e}^{3+}}$ cation contains exactly ${{6.022.10}^{23}}$ $F{{e}^{3+}}$ cation as Avogadro’s number and if we $2$ moles of $F{{e}^{3+}}$ ions, their weight is going to be twice the weight of one mole, if we have $0.5$moles the weight of the ions will the weight one mole.
$\to$ The molar masses of and of $F{{e}^{3+}}$ are the same $55.845g/mol$.
The mass of $F{{e}^{3+}}$ in mol of compound depends on the formula of the compound.
For example $11$mole of $Fe{{\left( N{{o}_{3}} \right)}_{2}}$ contains / mol of $F{{e}^{3+}}$ ions.
But $1-mol$ of $F{{e}_{2}}{{\left( S{{o}_{4}} \right)}_{3}}$ contains $2mol$ of $F{{e}^{3+}}$ ions. The molar mass is the mass of $1mol$ of atoms of that element for a covalent molecular compound.

Note: The mass of $F{{e}^{3+}}$ in $1$ mol of compound depends on the formula of the compound for compounds, the molecular mass is numerically the same as the mass of one mole of the compound in grams.