Question

Find the formula mass of the compound, then divide the individual element total by the total mass-move the decimal over two to change it to percentage FeCl3

Answer 1

Answer:

We first look up in the periodic table the molar mass of each individual element:

Fe: 55.84 g/mol

Cl: 35.45 g/mol

Then we calculate the molar mass of the compound:

$\rbrack M_{FeCl_3}=M_{Fe}+3.M_{Cl}=55.84\frac{g}{mol}+3.(35.45\frac{g}{mol})=162.19\frac{g}{mol}$

Finaly we calculate the percentage:

$\begin{gathered} Fe=\frac{55.84\frac{g}{mol}}{162.19\frac{g}{mol}}x100=34.4\% \\ Cl=\frac{3.\text{ }35.45\frac{g}{mol}}{162.19\frac{g}{mol}}x100=65.6\% \end{gathered}$

So finally, the percentages of each element in the molecule are:

Fe: 34.4%

Cl: 65.6%