Respuesta :
The empirical formula is the formula in which we use the least subscripts for each atom in it.
We have magnesium and bromine
The their molar masses are:
[tex]\begin{gathered} M_{Mg}=24.305g/mol \\ M_{Br}=79.904g/mol \end{gathered}[/tex]So, the number of moles of each in the sample is:
[tex]\begin{gathered} M_{Mg}=\frac{m_{Mg}}{n_{Mg}} \\ n_{Mg}=\frac{m_{Mg}}{M_{Mg}}=\frac{0.45g}{24.305g/mol}=0.018514\ldots mol \\ \\ M_{Br}=\frac{m_{Br}}{n_{Br}} \\ n_{Br}=\frac{m_{Br}}{M_{Br}}=\frac{1.5g}{79.904g/mol}=0.018772\ldots mol \end{gathered}[/tex]Their ratio is:
[tex]\frac{n_{Mg}}{n_{Br}}=\frac{0.018514\ldots mol}{0.018772\ldots mol}=0.9862\ldots\approx1[/tex]That is, their ratio is about 1:1, thus, the empirical formula is MgBr.
