Question

1) The structures for cyclopentasiloxane, benzyl alcohol, and glycerol are all found on the front page.

For each molecule, type in the blank the strongest intermolecular force experienced by a pure sample of that substance: dispersion forces, dipole-dipole forces, or hydrogen bonds.

water

hexane (C₆H₆)

cyclopentasiloxane

benzyl alcohol

glycerol

2) The structures for cyclopentasiloxane, benzyl alcohol, and glycerol are all found on the front page.

Rank each of the following molecules from MOST POLAR (1) to LEAST POLAR (5). Type the appropriate number from 1 to 5 in the blank.

water

hexane (C₆H₆)

cyclopentasiloxane

benzyl alcohol

glycerol

3) The structures for cyclopentasiloxane, benzyl alcohol, and glycerol are all found on the front page.

For each molecule, type in the blank the substance that the molecule will be most soluble in: water or hexane.

cyclopentasiloxane

benzyl alcohol

glycerol

A homogeneous solution is one in which all the components of the solution are miscible. Based on the information provided earlier in the case, please specify which one of the three products is not a homogeneous solution.

		Product 1
		Product 2
		Product 3

Answer 1

1)

The strongest intermolecular force experienced by a pure sample of that substance: dispersion forces, dipole-dipole forces, or hydrogen bonds.

water : water have dipole moment also, but strongest intermolecular force is Hydrogen bonds. Hydrogen bonds are a relatively strong intermolecular force and are stronger than other dipole- dipole forces

Hexane : non-polar compound so only intermolecular force is Dispersion forces (london forces)

cyclopentasiloxane : Dispersion forces

benzyl alcohol : Dispersion forces

Hydrogen bonding aren't only intermolecular force in alcohols. There are also dispersion forces and dipole-dipole interactions.Hydrogen bonding and dipole-dipole interactions will be much the same for all the alcohols, but the dispersion forces will increase as the alcohols get bigger. These attractions get stronger as the molecular size increases and have more electrons. That increases the sizes of the temporary dipoles that are set up.This is why the boiling points increase as the number of carbon atoms in the chains increases. It takes more energy to overcome the dispersion forces, and so the boiling points rise.

glycerol :  Hydrogen bonds. (Due to the presence of three -OH groups,glycerol molecules form an extensive network of intermolecular hydrogen bonds.)

2). Rank each of the following molecules from MOST POLAR (1) to LEAST POLAR (5) :

water (2)

hexane (5) : least polar (non-polar)

cyclopentasiloxane (4)

benzyl alcohol (3)

glycerol (1) -most polar

( Glycerol have 3 -C-O-H bonds : cummulative effect of these makes it more polar than water.

3).  Water or hexane solubility :

cyclopentasiloxane : Most soluble in Hexane.

benzyl alcohol :Most soluble in Water.

Glycerol : Most soluble in Water.

- Product of Benzyl alcohol and water mixing is not a homogeneous solution​​​​​​, as benzyl alcohol is moderately soluble in water.