UNIT 1-C INVESTIGATING THE CAUSE OF THE FISH KILL Section C.1 1. Define solubility - THE MAXIMUM AMOUNT OF SOLUTE THAT WILL DISSOLVE IN A GIVEN AMOUNT OF SOLVENT – AT A GIVEN TEMPERATURE. - EX. – SUGAR IN WATER AT 25C – SOLUBILITY IS 15g SUGAR / 100 g WATER
2. List the two factors that do not effect how much of a substance can dissolve?
- EVERYTHING DISSOLVES TO SOME EXTENT - THINGS THAT READILY DISSOLVE = SOLUBLE - THINGS THAT HARDLY DISSOLVE AT ALL = INSOLUBLE
3. Define saturated, unsaturated, and supersaturated solutions - SATURATED = THE SOLVENT HOLDS AS MUCH SOLUTE AS IT CAN - UNSATURATED = SOLVENT CAN HOLD MORE SOLUTE - SUPERSATURATED = UNSTABLE SITUATION CREATED WHERE SOLVENT HOLDS MORE SOLUTE THAN IT SHOULD
4. Know how to interpret data from a SOLUBILITY CURVE – Some help on Your Turn pg. 44 – (use figure 18, pg.42)
- What is the solubility of KNO3 at 80C? - At what temperature will the solubility of dissolved oxygen be 10 mg / 1000 mg of water ?
- How much KNO3 will dissolve in 200 g of water at 80C?
5. If you have a horizontal line of solubility what does that show for the substance graphed?
6. A solubility line with a steep incline tells you what about the relationship of the solute to water?
7. Each point plotted on the solubility line tells you what about that substance?
8. What do points below the line show?
9. Where on a solubility graph would you find a supersaturated solution?
10. What will happen to the solubility of a solid in water when the temperature of the water is lowered?
11. In contrast, what will happen to the solubility of a GAS when the temperature of the water is lowered?
12. List the two factors that a GAS’S solubility is dependent on? SECTION C.2 Concentration – a quantitative measurement of solute in a certain amount of solvent EXAMPLE – the concentration of sugar in a water solution – given in PERCENT SOLUTION =
( g solute / g solution) x 100
- PERCENT SOLUTION also called pph - Can also have ppt, and ppm solution concentrations
1) Another way to tell the concentration of a solution is by using percentage. What would be the % concentration of a solution containing 10 grams of salt dissolved in 90 grams of water? What would the concentration be in pph? In ppt? In ppm?
2) The concentration of seawater is 3g salt/100g of salt water. What is its concentration in pph. Show work and units______
3) At 26 °C water is saturated with oxygen when 8 mg(.008grams) of oxygen is dissolved in 1000g of water. What is the concentration of oxygen in ppm? Show work______
4) At 20 °C 1000g of water must have 5.4 mg or .0054g of Oxygen for fish to survive. Calculate this concentration in ppm. Show work and units 5) A solution which has .00005 g of lead ion dissolved in 1000g of water is considered dangerous to human health. Calculate the concentration in ppm Show work and units C.3 – OXYGEN What do aquatic organisms need to survive?
What interferes with the oxygen supply to aquatic organisms?
Describe how oxygen dissolves in water.
Describe photosynthesis.
List the photosynthesis equation.
What is the name of the oxygen - consuming bacteria that aquatic organisms compete with?
What do these organisms feed on?
When are aquatic creatures at risk?
Define DO.
The amount of dissolved oxygen that fish needs is?
Some fish require more oxygen than others What sort of water does trout live in? What sort of water do catfish live in? C.3 – OXYGEN - Every animal requires O2 for Aerobic respiration - Organisms that live in water get O2 dissolved in water, NOT the O in H2O - 3 ways O2 can become dissolved in the H2O - Direct contact w/ the atmosphere - Aeration – water “churned w/ air” - Photosynthesis of aquatic plants
6CO2 + 6H2O C6H12O6 + 6O2
- Aerobic bacteria use up O2 - Live off of wastes – natural or otherwise - Lots of “food” for bacteria = population explosion - Less O2 for other aquatic animals
- Dissolved Oxygen levels below 4 ppm = fishies die
C.4 – TEMPERATURE AND SOLUBILITY OF GASES - High temperatures = increased metabolism of fishies - Increased metabolism = more O2 use - Lower temperatures = decreased metabolism - Decreased metabolism = less O2 use - O2 gas solubility decreases at higher temperatures - Fish kills often happen in the summer! - High water temperature can be caused naturally – or by man – thermal pollution C.4 – TEMPERATURE AND SOLUBILITY OF GASES
As water temperature INCREASES, what happens to the solubility of gases?
Besides temperature, what other factor effects the solubility of gases?
If the temperature of the water increased 10 C what happens to chemical reactions of the fish?
Explain the purpose of refrigeration.
When water temperatures increase what happens to the temperature of the fish?
If the temperature of the water is raised, the fish's chemical reactions are what?
The fish now require what, since the temperature of the water is increased?
Consider aerobic bacteria, what effect does raising the temperature of water have on aerobic bacteria?
Explain what causes a fish kill after a warm spell.
What type of pollution would explain a raise in water temperature in Snake River? C.6 – ACID CONTAMINATION
ACIDS - Usually have a H+ that can be easily released into solution - H usually written first (i.e. HCl, H2SO4, H3PO4, HC2H3O2, H2CO3, HNO3) - Examples of uses ?
BASES - Usually have an OH- that can be easily released into solution - OH usually written last (i.e. NaOH, Ca(OH)2, Mg(OH)2, KOH) - Examples of uses?
- ACIDS and BASES can get together to make neutral solutions pH SCALE –tells us how to classify substances as ACIDIC, BASIC, or NEUTRAL
pH SCALE goes from 0 – 14 0 – 7 = ACIDIC 7 = NEUTRAL 7 – 14 = BASIC
Q. Where does ACID RAIN come from?
Q. Guess what area of the US is responsible for the majority of the ACID RAIN contamination of water sources in Canada? C.7 – IONS & IONIC COMPOUNDS Atoms that are charged are called ?
What are + ions called?
What are – ions called?
What do you get when you put positive ions and negative ions together to have a net charge of 0?
When we write formulas for IONIC COMPOUNDS, we always write the cations first, and anions last Example – NaCl CaCl2
When we name IONIC COMPOUNDS – 1. name the cation just like the element 2. drop the last few letters of the anion and add “ide” ending Example NaCl = Sodium Chloride CaCl2 = Calcium Chloride HF = ? KBr = ? Na2S = ?
2- Q. - What do we call these funky ions like (SO4) ? C.8 – DISSOLVING IONIC COMPOUNDS
Q. What must happen in order for ionic substances to dissolve in a particular solvent?
Q. What is it about water that makes it able to dissolve so many things?
C.9 – HEAVY METAL IONS Q. – What are the primary essential metals (minerals)?
Q. – What are the primary “heavy metals”?
Q. – What do these heavy metals do in our bodies?
Q. – What are some biological effects of metal poisoning? Q. – How do the heavy metals get into our water ?
LEAD
Q. – Where did the symbol for lead come from?
Q. - What are some of it’s uses?
Q. – How might lead have contributed to the fall of the Roman Empire?
Q. – What is the primary way urban children are exposed to Pb? MERCURY
Q. – Where did the symbol for mercury come from?
Q. – What are some of it’s uses?
Q. – What physical form of mercury is most dangerous?
+ Q. – Where does the highly toxic (CH3Hg) come from?
Q. – Where do you think the term “Mad as a Hatter” comes from?
CADMIUM
Q. – What are some of it’s primary uses?
Q. – What sort of biological damage does it cause?
Q. - What is the primary way Cd enters the body? Is it then excreted? C.11 – MOLECULAR SUBSTANCES
- There are 2 major types of compounds - IONIC – held together by (+) and (–) charged particles attracted to one another (i.e. NaCl) - MOLECULAR – held together by the sharing of electrons (i.e. H2O) - There are 2 major types of MOLECULAR COMPOUNDS - POLAR – unequal sharing of electrons (i.e. CH3OH) - NON-POLAR - equal sharing of electrons (i.e. N2)
Q. – What is one simple rule that can be used to determine the solubility of solutes in solvents?