1. Properties of Ionic and Molecular Compounds
Solubility and Properties of Water
Section 2.3

2. Objectives
Classify ionic and molecular compounds based on their properties
Use a solubility chart to predict whether an ionic compound is soluble in water
Relate the molecular structure of water to its properties

3. Solubility Solubility: the ability to dissolve (in our case, in water)
Aqueous (aq) : when something is very soluble
Solid (s) : when something is slightly soluble/doesn’t dissolve well
Decide this by using a solubility table:
page 57 in textbook and on your data sheet

4. Demonstration
Copy the following table into your notes and fill in during the demonstration:
silver nitrate
strontium nitrate
sodium iodide
sodium sulfate
barium iodide

5. How to use a solubility table
page 57 in textbook and on your data sheet
Break the compound up into its ions:
The negative ions (anions) are across the top
Find your negative ion and then look down into the chart to find the positive ion
“all” : all compounds with those ions
“most” : most compounds with those ions
“only with” : only compounds containing what’s listed
Which elements are group 1? Group 2?

6. Solubility Table
Find the solubility/state of the following compounds using the solubility table:
(NH4)2S
AgCl
PbSO4
Sr(OH)2
Fe(OH)3
Au(NO3)3
AgCH3COO
potassium carbonate
iron (III) nitrate
ammonium sulfite
lead (IV) bromide

7. Demo Results Which compounds produced solids?
Could we have predicted which ones would form solids?
Can you identify which compound made the precipitate? How?
What ions do I have? How will they recombine?

8. Properties of Water Water is polar
Has a positive (hydrogen) and a negative (oxygen) end
Bent shape and unequal sharing of electrons
What does this mean can happen?
Water molecules are attracted to one another
Because polar, has several important properties:
Boils at higher temp
Why is this important? Hint: Think of how much of the earth is covered in water
Bodies of water serve to regulate temperatures (absorb heat during the summer and release in winter)

9. Formation of Ice Is ice more or less dense than liquid water?
How do you know?
Water molecules spread out as it freezes making six-sided rings
Look at a snowflake: how many points does it have?
Space in between water molecules
Makes ice less dense
Why is this important? What might be affected if ice didn’t float?