Question

In which of the following species the bond is non-directional?
a. \[NC{{l}_{3}}\]
b. \[RbCl\]
c. \[BeC{{l}_{2}}\]
d. \[BC{{l}_{3}}\]

Answer 1

Hint: We can solve this question by keeping just one thing in mind that if two species form ionic bonds then it is non-directional in nature whereas covalent bonds on the other hand are directional. Compounds having covalent bonds have fixed geometry which is not the case with compounds having ionic bonds. So, we just need to look for compounds having ionic bonds.

Complete answer:
Ionic or electrovalent bonds are known as non-directional bonds, the meaning of non-directional can be explained in terms of geometry, these type of bonds doesn't have any special type of geometry, that is only attraction of positive and negative charge as we know ionic bonds made between metal which is positively charged and non-metal which is negatively charged.

In the given options because E.N. difference between only \[Rb\] and \[Cl\] enough to make ionic bonds, hence it proves that \[RbCl\] is an ionic compound.

Hence, The correct answer is option (B), \[RbCl\].

Note: Covalent bonds are formed between two non-metals or elements having high and equal electronegativity whereas ionic bonds are formed between a metal and non-metal. Molecules formed by covalent bonds have a low melting point as they have weak forces of attraction whereas those with ionic bonds have a high melting point. The same relationship exists for boiling points as well. This is because ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions or between two atoms with largely different electronegativities, and is the primary interaction occurring in ionic compounds.