What is the relative formula mass of aluminium chloride, AlCl3\text{AlCl}_3AlCl3?
Relative atomic mass (ArA_{\text{r}}Ar): Cl=35.5\text{Cl} = 35.5Cl=35.5, Al=27.0\text{Al} = 27.0Al=27.0.
62.5
98.0
133.5
187.5