What are the complete structures, including lone pairs, for the following compounds: C2H5OH, HOCH2CH2NH2, CH3NH2, and CH2Cl2?

To illustrate the complete structures of the compounds along with their lone pairs, let’s break down each compound individually:

1. C2H5OH (Ethanol)

The structure of ethanol includes an ethyl group (C2H5) bonded to a hydroxyl group (OH). The oxygen in the hydroxyl group has two lone pairs. Visual representation:

   H   H
    |   |
 H--C---C--OH
    |   |
   H   H
   (O has 2 lone pairs)

2. HOCH2CH2NH2 (2-Aminoethanol)

This compound contains an amino group (NH2) and a hydroxyl group (OH) on an ethylene backbone. The oxygen has two lone pairs and the nitrogen has one lone pair. Visual representation:

   H   H   H
    |   |   |
 H--C---C--N--H
    |   |   |
   H   OH
   (O has 2 lone pairs, N has 1 lone pair)

3. CH3NH2 (Methylamine)

Methylamine contains a methyl group (CH3) attached to an amino group (NH2). The nitrogen in the amino group carries one lone pair. Visual representation:

 H   H
  |   |
H--C--N--H
  |   |
 H   H
  (N has 1 lone pair)

4. CH2Cl2 (Dichloromethane)

Dichloromethane is made from a carbon atom bonded to two chlorine atoms and two hydrogen atoms. The carbon has no lone pairs, but the chlorine atoms each have three lone pairs. Visual representation:

    H
    |
H--C--Cl
    |   |
    H   Cl
    (Cl has 3 lone pairs each)

Understanding these structures helps in visualizing the molecular geometry and the presence of lone pairs, which can affect the reactivity and properties of these compounds.