Question

Element $XandY$ have common oxidation states as $-3,+1$ respectively. The most common compound formed by $X$ and $Y$ is:

• A. $XY$
• B. $X_{3}Y$
• C. $X{Y}_3$
• D. $X_3{Y}_3$

Answer 1

The correct option is C $X{Y}_3$

$X$ has oxidation state $-3$ which means it can accomodate 3 more electrons in its shell to attain inert gas configuration. Similarly, $Y$ can lose one electron to get stable noble gas configuration.
Therefore 3 units of $Y$ can combine with a unit of $X$ to form most probable compound, i.e., $X{Y}_3$