Question

Element X is a metal with a valency 2.

Element Y is a non-metal with valency 3.

(ii) If Y is a diatomic gas write the equation for the direct combination of X and Y to form a compound?

Answer 1

• Metals are electropositive in nature which means they donate electrons present in their outermost shell thereby forming ions with a positive charge
• Sine X is metal and has a valency of 2, which means that it can donate 2 electrons from its outermost shell.
• The reaction of X losing its outermost electron is,

$X\to X^{2+}+2e^{-}$

• Non-metals tend to accept electrons to their outermost orbitals to obtain a stable configuration.
• Since Y is a nonmetal it will accept 3 electrons and thereby making negatively charged ions.
• The reaction is,

$Y+3e^{-}\to Y^{3-}$

• If Y is a diatomic molecule it will accept a total of 6 electrons from the metals. But one metal can only donate 2 electrons so the metal that is going to combine with Y is 3.
• The equation can be given as,

$Y_2+3X\to X_3{Y}_2$

• X and Y combine to form,

$Y_2+3X\to X_3{Y}_2$