Question

c) write the vsepr formula for the n - atom as the central atom in glycine. what is the approx. c - n - h bond angle. explain on the basis of vsepr theory. what is the approx. o - c - o bond angle. explain on the basis of vsepr theory.

Explanation:

Step1: Determine VSEPR formula for N - atom

The N - atom in glycine has 3 bonding pairs (to 2 H atoms and 1 C atom) and 1 lone pair. The VSEPR formula is \(AX_{3}E\) (where \(A\) is the central atom, \(X\) is the bonded atom, and \(E\) is the lone pair).

Step2: Predict C - N - H bond angle

For \(AX_{3}E\) geometry (trigonal pyramidal), due to the repulsion between the lone pair and bonding pairs (\(lp - bp>bp - bp\)), the bond angle is less than \(109.5^{\circ}\). The approximate \(C - N - H\) bond angle is \(107^{\circ}\).

Step3: Analyze O - C - O bond angle

The central C atom in the carboxyl group (\(-COOH\)) has \(sp^{2}\) hybridization ( \(AX_{3}\) VSEPR formula, trigonal planar geometry). The approximate \(O - C - O\) bond angle is \(120^{\circ}\) because in \(sp^{2}\) hybridization (trigonal planar according to VSEPR, when there are 3 bonding pairs and no lone pairs around the central atom, the bond angles are \(120^{\circ}\)).

Answer:

• VSEPR formula for N - atom: \(AX_{3}E\)
• Approximate \(C - N - H\) bond angle: \(107^{\circ}\)
• Approximate \(O - C - O\) bond angle: \(120^{\circ}\)