Miscibility and Solutions

The substance getting dissolved

• Solvent

• Solute

• Solution

• Mixture

How well two or more substances mix together

• Solution

• Mixture

• Miscibility

• Solvent

The substance that does the dissolving

• Solute

• Solvent

• Solution

• Miscibility

Is Bromine a polar or non-polar molecule?

• Polar

• Non-Polar

Answer explanation

Bromine must be non-polar since both bromine atoms have the same electronegativity so the two electrons in the covalent bond are shared equally between the two atoms.

What intermolecular attraction is between the ethanol molecules in ethanol?

• Dispersion Forces

• Dipole-Dipole Forces

• Hydrogen Bonding

Answer explanation

The presence of the polar hydroxyl group (-OH) means that hydrogen bonds can form between the partial positive on the hydrogen bonded to the oxygen and the partial negative charge on the oxygen atom in another molecule.

Which molecule would be more likely to be miscible in water?

• NH₃

• CH₄

• 

Answer explanation

Methane and Benzene are both non-polar. As water is polar then ammonia will be more soluble as the bonds between water molecules will be able to be overcome and hydrogen bonds will also be able to be formed between water and ammonia atoms. "like dissolves like"

Will octane and cyclohexane be miscible?

• Yes

• No

Answer explanation

They are both symmetrical non-polar molecules and hence are held together with dispersion forces. As like dissolves like", the dispersion forces will be able to form also between octane and cyclohexane allowing the molecules to intermingle.

Look up the structures of methyl propanoate and butanoic acid. Which one will be more miscible in water?

• methyl propanoate

• butanoic acid

Answer explanation

Butanoic acid is more miscible due to the more polar COOH group which is able to form hydrogen bonds with water. methyl propanoate is only able to form dipole -dipole interactions.

Look up the structures of ethanoic acid and heptanoic acid. Which one will be more miscible in water?

• ethanoic acid

• heptanoic acid

Answer explanation

Ethanoic acid will be more miscible because it is the smaller molecule. It is more difficult for water to surround the larger heptanoic acid molecule especially the non-polar end of the molecule where dispersion forces are the main interactions between molecules.

Hydrophilic means

• water hating

• water loving