1. 7.5 – NOTES Inappropriate Levels in Water

2. C.8 Inappropriate Heavy-Metal Ion Concentration in River?
True or False: Many metal ions, like Fe, K, Ca, and Mg are necessary in small quantities to keep us healthy
True
Heavy metals are so named because they have a very high atomic mass

3. Not all dissolved metal ions are helpful
As they get farther up the food chain, concentrations increase and become more difficult to remove
Green chemistry
Practices which prevent pollution by eliminating the production and or use of hazardous substances

4. C.9 Inappropriate pH Levels in River?
pH scale – a way to describe how acidic, basic, or neutral a substance is
Most pHs fall in range of 0-14
On the pH scale, each number is 10 times stronger than the number before it
Acids Bases
Contain H+ ions contain OH-
HNO3, H2SO NaOH, Ca(OH)2
Litmus paper turns red litmus turns blue
pH value of lower than pH values above 7
sour slippery

6. Strong acids and bases conduct electricity, both are corrosive
Rainwater is slightly acidic
Drinking water is between 6.5 and 8.5
Fish can survive in pHs of 5-9

7. C.10 Inappropriate Molecular-Substance Concentration in River?
Molecular substances are composed of molecules and don’t dissolve into ions
Can exist as solids, liquids, or gases 
Most contain all nonmetal components
Molecular substances are usually nonpolar, which means they equally share electrons

8. Electronegativity
An atoms ability to attract shared electrons in a bond
The larger the difference, the more likely ions are to form
Solubility follows the rule “Like dissolves like”
Polar substances will dissolve polar compounds
They will also dissolve ionic compounds, due to the similarity of having charges.
Nonpolar solvents will dissolve only nonpolar compounds.

10. C.12 Inappropriate Dissolved Oxygen Levels in Water?
How solids dissolve depends on both temperature and quantity;
When temperature increases, the solubility will increase
Pressure does not affect the solubility of solids; solids are not able to be compressed
Gas solubility is affected by both pressure and temperature.
An increase in temperature will decrease the solubility of a gas, while an increase in pressure will increase solubility.
The effect of temperature on the solubility of a gas is the opposite of the effect on a solid.

12. C.13 Temperature, Dissolved Oxygen, and Life
Fish are cold-blooded, meaning their body temperature changes with the water temperature
A rise in body temperature increases the metabolism, which means an increase in the fish's needs for oxygen and other resources
Increased water temperature can come from:
Sun
Industry – cooling power plants

13. Too much dissolved oxygen results in too much dissolved nitrogen, which results in gas-bubble trauma in fish ( % supersaturated O2 and N2)
Gas bubbles form in blood and tissue of fish
Causes blocked blood flow in fish and kills them