Question: $\mathrm{Fex}_{2}$ and $\mathrm{Fey}_{3}$ are known when $\mathrm{x}$ and $\mathrm{y}$ are:
$\mathrm{x}=\mathrm{F}, \mathrm{Cl}, \mathrm{Br}, \mathrm{I}$ and $\mathrm{y}=\mathrm{F}, \mathrm{Cl}, \mathrm{Br}$
$x=F, C l, B r$ and $y=F, C l, B r, I$
$\mathrm{x}=\mathrm{Cl}, \mathrm{Br}, \mathrm{I}$ and $\mathrm{y}=\mathrm{F}, \mathrm{Cl}, \mathrm{Br}, \mathrm{I}$
$\mathrm{x}=\mathrm{F}, \mathrm{Cl}, \mathrm{Br}, \mathrm{I}$ and $\mathrm{y}=\mathrm{F}, \mathrm{Cl}, \mathrm{Br}, \mathrm{I}$
Correct Option: 1
Solution:
