C2H5N - Learnexams

C2H5N

a) Draw Lewis Structure with lines

b) Molecular Geometry (VSEPR) sketch and bond angles. Show resultant polarity, if applicable

c) State the central atom

d) State the number of single, double and triple bonds, lone pairs and pi bonds

e) State hybridization of central atom

f) Names of electron arrangement and of molecular geometry

The correct answer and explanation is :

Let’s break down the molecule C2H5N, which is an ethylamine (also called ethanamine). Here is the step-by-step breakdown of your questions:

a) Lewis Structure with Lines:

To draw the Lewis structure of C2H5N (Ethylamine):

Count valence electrons:

Carbon (C) has 4 valence electrons × 2 (for two carbons) = 8
Hydrogen (H) has 1 valence electron × 5 (for five hydrogens) = 5
Nitrogen (N) has 5 valence electrons × 1 (for one nitrogen) = 5
Total: 8 (C) + 5 (H) + 5 (N) = 18 valence electrons

Structure:
The two carbon atoms (C) are bonded by a single bond. Each carbon atom is bonded to hydrogen atoms. The nitrogen (N) is bonded to the second carbon atom with a single bond and also has a lone pair of electrons. Here’s the structure:

   H   H
   |   |
   H-C-C-N-H
       |
       H

The bonds are:

C-C: single bond
C-H: single bonds
N-H: single bonds

b) Molecular Geometry (VSEPR) and Bond Angles:

The molecule C2H5N consists of a C-C chain with an NH2 group attached to the second carbon. The nitrogen (N) is the central atom in this structure.

Central atom: Nitrogen (N)
Electron pairs around nitrogen: Nitrogen has one lone pair and forms three single bonds with carbon and hydrogen atoms.
Geometry of Nitrogen (N): Since nitrogen has three bonding pairs and one lone pair, the geometry around nitrogen is trigonal pyramidal. The bond angles are less than 109.5° (around 107°).

c) Central Atom:

The central atom in this molecule is Nitrogen (N). It is directly bonded to the second carbon in the ethyl group and has a lone pair of electrons.

d) Bonds, Lone Pairs, and Pi Bonds:

Single Bonds:
C-H (5 bonds)
C-C (1 bond)
C-N (1 bond)
N-H (2 bonds)
Double Bonds: None
Triple Bonds: None
Lone Pairs: Nitrogen has 1 lone pair of electrons.
Pi Bonds: None (All bonds are sigma bonds in this molecule).

e) Hybridization of Central Atom:

The central atom is Nitrogen (N). Since it has three sigma bonds and one lone pair, the hybridization of nitrogen is sp³. This hybridization leads to the trigonal pyramidal molecular geometry.

f) Electron Arrangement and Molecular Geometry Names:

Electron Arrangement: The electron geometry around nitrogen is tetrahedral because it has four regions of electron density (three bonds and one lone pair).
Molecular Geometry: The actual molecular geometry (considering only the positions of the atoms) is trigonal pyramidal due to the presence of one lone pair on nitrogen.

300-Word Explanation:

Ethylamine (C2H5N) is a simple organic molecule with a nitrogen atom bonded to an ethyl group (C2H5). The molecule’s Lewis structure reveals a central nitrogen atom bonded to two hydrogen atoms and one carbon atom, with a lone pair of electrons on nitrogen. The molecule follows the basic principles of bonding and electron configuration.

To determine the molecular geometry, we use VSEPR (Valence Shell Electron Pair Repulsion) theory. The nitrogen atom is the central atom in this molecule and has three single bonds (to two hydrogens and one carbon) and one lone pair of electrons. According to VSEPR, regions of electron density around a central atom arrange themselves to minimize repulsion. In this case, the nitrogen atom has four regions of electron density: three bonding pairs and one lone pair. This leads to a tetrahedral electron geometry. However, because the lone pair is not visible in the molecular structure, the molecular geometry is described as trigonal pyramidal.

The bond angles around nitrogen are slightly less than 109.5°, typically around 107°, due to the lone pair occupying more space than the bonding pairs. The molecule is polar due to the presence of the lone pair on nitrogen, which creates an unequal distribution of charge, with the nitrogen end being slightly negative and the hydrogen end being slightly positive. The sp³ hybridization of nitrogen contributes to the tetrahedral electron arrangement, and the trigonal pyramidal geometry reflects the molecular structure after accounting for the lone pair.

Thus, ethylamine has a polar molecular structure with a trigonal pyramidal geometry, resulting in a dipole moment.