In gaseous triethyl amine "-C-N-C-" bond angle is _____ degree.

Answer

To determine the C-N-C bond angle in gaseous triethylamine, we can follow these steps:

### Step 1: Identify the Structure of Triethylamine
Triethylamine (N(CH2CH3)3) consists of a nitrogen atom bonded to three ethyl groups. The nitrogen atom has a lone pair of electrons.

### Step 2: Determine the Hybridization of Nitrogen
The nitrogen atom in triethylamine is sp³ hybridized. This is because it is bonded to three ethyl groups and has one lone pair of electrons.

### Step 3: Understand the Effect of Lone Pair on Bond Angles
In a typical sp³ hybridized molecule like ammonia (NH3), the bond angle is approximately 109.5 degrees. However, the presence of a lone pair of electrons decreases the bond angle due to lone pair-bond pair repulsion. In ammonia, the bond angle is about 107 degrees because of this effect.

### Step 4: Consider the Influence of Ethyl Groups
In triethylamine, the three ethyl groups are bulky. These bulky groups will exert steric repulsion on each other, which can cause the bond angles to increase slightly compared to ammonia.

### Step 5: Calculate the C-N-C Bond Angle
Given that the bond angle in ammonia is approximately 107 degrees due to the lone pair, and considering that the bulky ethyl groups will cause an increase in the bond angle, we can conclude that the C-N-C bond angle in triethylamine will be larger than 107 degrees.

Through analysis, it is determined that the bond angle is approximately 108 degrees.

### Final Answer
The C-N-C bond angle in gaseous triethylamine is **108 degrees**.

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