Question

Arrange the compounds in order of decreasing solubility in water. a) butan b) ethyl methyl ether

c) propanol.

Answer 1

The compounds ethyl methyl ether, 2-methylpropane (isobutane), and acetone are ordered in increasing boiling points based on their intermolecular forces and molecular structure: isobutane has the lowest followed by the ether, and acetone has the highest boiling point.

Step-by-step explanation:

The boiling points of compounds are influenced by the type of intermolecular forces they exhibit, such as hydrogen bonding, dipole-dipole interactions, and London dispersion forces. Molecular weight and structure (branching) also play significant roles in determining boiling points. To arrange the compounds ethyl methyl ether (CH3OCH2CH3), 2-methylpropane (isobutane, (CH3)2CHCH3), and acetone (CH3COCH3) in order of increasing boiling points, we need to consider these factors.

• Ethyl methyl ether has a relatively low boiling point because ethers have ether linkages that do not allow for hydrogen bonding with other ether molecules. However, it can engage in dipole-dipole interactions.
• 2-Methylpropane (isobutane) is an alkane with only London dispersion forces, which are the weakest intermolecular forces, but its branched structure makes it have a lower surface area and therefore a lower boiling point compared to straight-chain alkanes of similar molecular weight.
• Acetone has a carbonyl group that allows for stronger dipole-dipole interactions compared to ethers and alkanes, as well as the possibility of hydrogen bonding with water molecules. Additionally, the presence of oxygen increases the polarity of the molecule, leading to a higher boiling point.

Thus, the order of increasing boiling points for these compounds is:

1. 2-Methylpropane (isobutane)
2. Ethyl methyl ether
3. Acetone