Solubility

Question 1

What happens when something dissolves?(2)

Answer 1

• Bonds WITHIN solvent and solute break

- New bonds BETWEEN solvent and solute are made

Question 2

When do solutes dissolve best in solvents?

Answer 2

When they have similar intermolecular forces

Question 3

Explain why a solute won’t dissolve in a solvent (2)

Answer 3

• Not energetically feasible

- More energy needed to break bonds than make bonds (bonds broken are much stronger than bonds formed)

Question 4

What are the 2 main types of solvent and give examples

Answer 4

Polar (water) and Non-Polar (hexane)

Question 5

What substances can dissolve in polar solvents and why?

Answer 5

• Ionic Substances

- Ion-dipole bonds formed are strong enough to dissolve solid

Question 6

Why can’t Polar molecules dissolve in non-polar solvents?(2)

Answer 6

• Doesn’t interact strongly enough with ions to pull them away from lattice
• electrostatic forces between ions are much stronger than anyother bond which could form between ions and non polar solvent

Question 7

What substances can dissolve in non polar solvents and why?

Answer 7

• Covalent substances

- intermolecular bonds in covalent molecules are weak so they can be easily broken

Question 8

Why do covalent substances tend not to dissolve in polar solvents?

Answer 8

Hydrogen bonds between water molecules stronger than bonds made with covalent substance

Question 9

What do you call solvents which aren’t water?

Answer 9

Non-aqueous solvents