Given C2H60;
Some properties of the two compounds are listed below;
Compound X: Melting Point
Compound Y: -114C | -118C
X: Boiling Point
y: 78C | -22C
X: Net Dipole?
Y: Yes | Yes.
X: Functional group
Y: Alcohol | Ether.
i. Draw plausible Lewis structure of compounds X and Y.
ii. In Which compound are intramolecular forces stronger? Justify your answer.
iii. Is either compound capable of hydrogen bonding? If so, draw a schematic representation of a typical hydrogen bond in this substance.
iv. Which compound is likely to be more soluble in water? Justify your answer.
See comment above.
i. To draw the plausible Lewis structures of compounds X and Y:
Compound X (Alcohol):
C2H6O can be written as CH3CH2OH
The Lewis structure for CH3CH2OH (ethanol) would be:
H H O
| | ||
H-C-C
| |
H H
Compound Y (Ether):
C2H6O can also be written as (CH3)2O
The Lewis structure for (CH3)2O (dimethyl ether) would be:
H H
| |
H-C-O-C-H
| |
H H
ii. To determine which compound has stronger intramolecular forces, we need to compare the types of intermolecular forces present in both compounds:
- Compound X (ethanol) has a hydroxyl group (-OH), which can form hydrogen bonds with other ethanol molecules, creating strong intermolecular forces.
- Compound Y (dimethyl ether) does not have a hydrogen atom bonded to an electronegative atom like oxygen or nitrogen, so it cannot form hydrogen bonds. It only has London dispersion forces or van der Waals forces, which are generally weaker than hydrogen bonding.
Based on this analysis, compound X (ethanol) is likely to have stronger intramolecular forces.
iii. Compound X (ethanol) is capable of hydrogen bonding. A schematic representation of a typical hydrogen bond in ethanol would be:
H H
| |
H-O-H
| |
H H
In this representation, the dashed line represents a hydrogen bond formed between the hydrogen atom of one ethanol molecule and the oxygen atom of another ethanol molecule.
iv. Compound X (ethanol) is more likely to be soluble in water. This is because ethanol has a hydroxyl group (-OH) that can form hydrogen bonds with water molecules. These hydrogen bonds can help to dissolve ethanol in water. On the other hand, compound Y (dimethyl ether) does not have a hydrogen atom bonded to an electronegative atom, so it cannot form hydrogen bonds with water. Therefore, ethanol (compound X) would be more soluble in water compared to dimethyl ether (compound Y).