1. 7.4 – NOTES Solution Concentration

2. C.4 Dissolving Ionic Compounds
Water molecules are electrically polar
This means the charges on the atoms in the molecule are shared unequally.
One end is more positive (+) and the other is more negative (-)
Instead of having full charges like ionic compounds, the atoms in a polar molecule have partial charges.
The partial charges equal out, making the molecule electrically neutral

3. Water molecules look like

4. Polar substances are attracted to polar substances and will dissolve many things
Water dissolves by pulling molecules away from the top of the other substances until there is nothing left for the water to pull away from

5. C.6 Solution Concentration Solution concentration
The quantity of solute dissolved in a specific quantity of solvent or solution
Expressed as a percent
g solute x 100 g solution = g solute + g solvent
g solution

6. Equal to pph (parts per hundred)
Example: A common IV saline solution used in medical practice contains 4.5 g NaCl dissolved in g of water. What is the concentration of this solution, expressed as a percent by mass?

7. Parts per million (ppm) or parts per billion (ppb)
Used to describe levels of contaminants in water or other trace elements
As a fraction, they are expressed as
Ppm = x _ ppb = x _
1,000, ,000,000,000