1. Do Now
From the list below, select the answers to the following questions:
i) diamond ii)graphite iii) iodine
Iv)sodium chloride v) silicon dioxide
A) which solid conducts electricity
B) which solid has the lowest melting point?
C)Which substance conducts electricity when molten?
D) which substances are covalent network solids

2. A) graphite
B) iodine
C) sodium chlordie
D) diamond, graphite, silicon dioxide

3. Solubility
Y12 Chemistry

4. Vocab SOLUBILITY - How likely a solid will dissolve in a liquid
SOLUTE - the dissolving solid
SOLVENT - the liquid

5. Intermolecular Forces
The forces which attract molecules to each other

6. Water A very polar molecule
Oxygen is very electronegative and Hydrogen is NOT very electronegative
O-H bond is very polar

7. Water
The electrons involved in the bond sit very close to the oxygen atom
This leaves the hydrogen atom as a ‘bare’ proton
This makes for a VERY polar moleucle

8. Water - Hydrogen Bonding
The ‘bare’ proton of the H atom is strongly attracted to a lone pair of electrons on the O atom
This holds the water molecules together in clusters
HYDROGEN BONDING

9. Dissolving
For a substance to dissolve, the solute to solvent interactions must be similar or stronger than the forces within the solvent and solute.

10. A polar substance dissolving

11. A polar substance dissolving

12. A polar substance dissolving

13. A polar substance dissolving

14. An ionic solid dissolving

15. An ionic solid dissolving

16. An ionic solid dissolving

17. An ionic solid dissolving

18. Non-Polar dissolving non-polar
Organic solvents such as cyclohexane are non polar molecules.
They will dissolve other non polar substances because their intermolecular forces are similar (weak).

19. Why they don’t like each other
Polar molecules won’t mix with non-polar.
Because the polar molecules are more attracted to themselves than the non-polar molecules they tend to stick together.

20. Practical
Page 55-57
You are NOT writing a report, we are just going to test the different solutes in the two different solvents to see which solutes are soluble.
Draw a results table and then complete the questions.