Question

A substance that can donate a pair of electrons to form a covalent bond is known as a(n) _____ base.

Answer 1

Answer : A substance that can donate a pair of electrons to form a covalent bond is known as a(n) Lewis-base.

Explanation :

According to the Lewis acid-base theory,

Lewis acid : It is a substance that can accepts pairs of electrons to form a covalent bond.

Lewis-base : It is a substance that can donates pairs of electrons to form a covalent bond.

For example :

$H^++OH^-\rightarrow H_2O$

In this reaction, $H^+$ ion is Lewis-acid and $OH^-$ ion is a Lewis-base. The $OH^-$ ion donates electrons to $H^+$ ion to form $H_2O$.

Hence, a substance that can donate a pair of electrons to form a covalent bond is known as a(n) Lewis-base.

Answer 2

A substance that can donate a pair of electrons to form a covalent bond is known as a Lewis base. It is any substance that can donate a pair of nonbonding electrons. The Lewis theory suggests that acids react with bases to share a pair of electrons with no change of oxidation numbers of any atoms.