Question

Identify the different types of bonds present in quaternary ammonium salts.

• A. Covalent
• B. Ionic
• C. Covalent and co-ordinate
• D. covalent, co-ordinate and ionic

Hint:

In R4N+ X-, one N-R bond is formed from the lone pair (coordinate) and the ion pair is held by ionic bonding.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
A quaternary ammonium salt has the formula \(\text{R}_4\text{N}^+\text{X}^-\). We need to list every kind of bond inside this salt.

Step 2: Bonds inside the cation:
The N atom has 5 valence electrons. Three are used for three covalent N-R bonds, and one lone pair remains. This lone pair forms the fourth N-R bond as a coordinate (dative) bond, which gives \(\text{N}^+\). The R-groups themselves are joined internally by covalent bonds.

Step 3: Bond between ions:
The positive \(\text{R}_4\text{N}^+\) cation and the negative \(\text{X}^-\) anion attract each other by an ionic bond.

Step 4: Compare the options.
Covalent alone (A) and ionic alone (B) miss part of the structure. "Covalent and coordinate" (C) leaves out the ionic bond to \(\text{X}^-\). Only D lists all three.

Final Answer:
Quaternary ammonium salts contain covalent, co-ordinate and ionic bonds. \[ \boxed{\text{(D) }\text{covalent, co-ordinate and ionic}} \]