November 30, 2011 Unit B: Matter and Chemical Change Corn Syrop w/ Food Colouring Baking Soda Water Investigation 1. Create a density tower more or less following the instructions on page 91 with the following exceptions: - use a graduated cylinder not a 250 mL beaker - use only 15 mL of syrup, water, and oil and only 5 mL of baking soda 2. Be very careful & gentle so as not to mix each layer. When adding the water, tip the beaker and allow it to run down one side. 3. Add a few drops of coloured vinegar to: a) the oil layer. Record observations b) the water layer. Record observations c) the syrup layer. Record observations Oil
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November 30, 2011
Unit B: Matter and Chemical Change
Corn Syrop w/Food Colouring
Baking Soda
Water
Investigation
1. Create a density tower more or less following the instructions on page 91 with the following exceptions:
- use a graduated cylinder not a 250 mL beaker- use only 15 mL of syrup, water, and oil and only 5 mL of baking soda
2. Be very careful & gentle so as not to mix each layer. When adding the water, tip the beaker and allow it to run down one side.
3. Add a few drops of coloured vinegar to: a) the oil layer. Record observationsb) the water layer. Record observationsc) the syrup layer. Record observations
Oil
November 30, 2011
1.1 Safety in the Science Class
Symbols are used to indicate how dangerous a substance is:
Caution Warning Danger
1.1 Safety in the Science Class
The symbols can be combined with pictures to indicate the type of danger (p.94)
Warning:Flammable
Caution:Explosive
Warning:Toxic
Danger:Irritant
Caution:Corrosive
Danger:Electrical
Warning:Biohazard
November 30, 2011
1.1 Safety in the Science Class
WHIMIS (Workplace Hazardous Materials Information System) has a slightly different set of symbols:
By law, all workplaces, schools, etc require MSDS sheets for all
chemicals stored and used there. MSDS sheets use
WHMIS symbols
1.1 Safety in the Science Class
Examine the picture on page 93. In pairs or small groups, identify as many safety concerns as possible.
For each concern, suggest a possible solution.
Review Safety Consideration on page 95
Lego LabSafety Rap
Other: - Goggle Sanitation & Storage- Prep Room Tour
- MSDS Binder- Eye Wash Station- Broken Glass
- Fire Evacuation / Lockdown
November 30, 2011
1.2 Organizing Matter
Matter: Anything that has mass and occupies space. Matter occurs in three different states:
Can you correctly namethe physical changes thatthese arrows represent?
1.1 Organizing Matter
All matter has both physical and chemical properties.- Physical properties describes a substance's characteristics when by itself- Chemical properties describe how a substance reacts with other substances
When writing the chemical formulas:- subscript numbers indicate the number of atoms of each element (if more than one)- Italicized and subscript (s), (g), (l) are used to show state
Compound Elements # of Atoms Statein Compound in each Element
CaO(s)
CaCl2(s)
Al2O3(s)
CH4(g)
KCl(s)
Mg3(BO3)2(s)
3.1 Naming Chemical Compounds
Homework: p.143 #1-5
November 30, 2011
3.2 Ionic Compounds
An ion is an atom that has become electrically charged due to the gain or loss of an electron
Review: When atoms have the same number of protons (+) and electrons (-) they have no charge
Ex. Chlorine (Cl) has _____ protons and _____ electrons
Ex. Calcium (Ca) has _____ protons and _____ electrons
Ex. What happens is Cl gains one electron? Is it still neutral or does it have a charge?
Ex. What happens if Ca loses two electrons?
3.2 Ionic Compounds
(+) and (-) signs are placed in the upper right hand corner of the element symbol to indicate it's charge.
Here are some common ions. Fill in the table indicating whether they have gained or lost electrons or by writing the symbol:
Symbol Gained / Lost Electrons
H+
O2-
Na+
Copper loses 2 electrons
Sulfur gains 2 electrons
November 30, 2011
3.2 Ionic Compounds
Common ion charges are shown in the periodic table in the upper right corner of each element. Can you see any patterns?
Individual atoms can be ionic or groups of atoms can form ions. Ions with more than one element are called polyatomic.
Here are some common polyatomic ions:
CO32- = Carbonate
SO42- = Sulfate
Some elements can also form different ions depending on the number of electrons they lose or gain.
For example, Copper can lose either one or two electrons and become either
Cu+ or Cu2+
3.2 Ionic Compounds
Ionic compounds are made by combining a metal ion (with a positive charge) and a non-metal ion (with a negative charge)
Examples:
Na+ + Cl - NaCl (Sodium Chloride)
Li+ + Cl - LiCl (Lithium Chloride)
Ca2+ + Cl - CaCl2 (Calcium Chloride)
Ca2+ + CO 32- CaCO3 (Calcium Carbonate)
November 30, 2011
3.2 Ionic Compounds
Ionic compounds are neutral and thus the charges need to be balanced (equal zero)
Examples:
Barium + Chlorine =
Magnesium + Iodine =
Copper (II) + Chlorine =
Potassium + Carbonate =
3.2 Ionic Compounds
Lab: Properties of Ionic Compounds
ObservationsTest #1Distilled Water
Test #2Glucose Solution
Test #3Sodium SulfateSolution
Conclusions: Ionic compounds conduct electricity
November 30, 2011
3.2 Ionic Compounds
Lab: Properties of Ionic CompoundsUse the Setup described on page 145 of the textbook.
Changes to the lab:
You will be observing the reactions that occur in the petri dish with three different solutions:
1. distilled water2. sugar solution (non-ionic compound) - mix in 1 sm. teaspoon3. sodium sulfate solution (ionic compound) - mix in 1 sm. teaspoon
*Rinse out petri dish in between each test*Use approx. 4-6 drops of bromothymol blue (universal indicator) for each test
Conclusion: Which compounds are good electrical conductors? What happens when an electrical current is allowed to travel through water?
3.2 Ionic Compounds
Naming Ionic Compounds:
When naming ionic compounds, the name of the metal (first element) remains the same and the name of the non-metal ends with '...ide'
Also, when there is more than one ion charge possible (copper, iron etc), we use roman numerals to indicate which charge:
Ex. BaI2
Sc2S3
Ex. FeCl3
FeCl2
November 30, 2011
3.2 Ionic Compounds
Homework:
p.149 #1-5, 7-9
3.3 Molecular Compounds
Molecular compounds are different from ionic compounds in that they:
- are made when non-metals combine (as opposed to ionic compounds which are a metal and a non-metal)- can be solid, liquid, or gas at room temperature- are insulators (poor conductors)- low melting and boiling points
Molecular compounds don't have have ion charges so they are not as easy to predict as ionic compounds.
Subscript numbers are still used to indicate the number of atoms:
Ex. NH3, C6H12O6, H2O, H20, H2
November 30, 2011
3.3 Molecular Compounds
Naming Molecular Compounds:1. The first element uses the element's name2. The second element has the suffix '-ide'3. We use a prefix when there is more than one atom:
mono = 1di = 2tri = 3tetra = 4penta = 5
4. The exception to rule #3 is that when there is only one of the first atom, we don't use 'mono'
Ex. H2OH2O2
CCl4PF5
3.3 Molecular Compounds
Homework: p.153 # 1-7p.154 # 2-14
November 30, 2011
4.1 Chemical Reactions
Reactants: materials at the start of a chemical reaction
Products: new materials produced by the reaction
Endothermic: a chemical reaction that absorbs heat energy (gets colder)
Exothermic: a chemical reaction that releases heat energy (gets warmer)
Lab Skills- Using a scale- Careful not to cross contaminate- Using a graduated cylinder
Precautions- bromothymol blue will stain your clothes (and everything else)- Don't let pressure build up in bag
In groups, conduct the lab according to the procedure. Try it again, this time leaving the bag open during the reaction. As a group, answer the analysis questions and form a conclusion.
4.2 Conservation of mass in Chemical Reactions
Law of Conservation of Mass: matter is not created or destroyed in a chemical reaction.
The mass of the reactants always equals the mass of the products.
Open System: products are allowed to escape
Closed System: products are trapped / retained
Homework: #4-7, 9, 10
November 30, 2011
4.3 Factors Affecting the Rate of Chemical Reations
Who can make the juice the fastest?
4.3 Factors Affecting the Rate of Chemical Reations
There are 4 factors that affect how quickly a reaction occurs:
1. Concentration of the reactants
2. Temperature of the reactants
3. Surface area of the reactants
4. Presence of a CatalystA catalyst is a substance that helps a reaction
go faster. In a biology context, these are calledenzymes.
Which makes the reaction go faster? (Circle one)
High Concentration / Low Concentration
Cold Reactants / Warm Reactants
High Surface Area / Low Surface Area
Catalyst Present / Catalyst Absent
90% HCl 10% HCl
5oC 30oC
Asprin in Tablet Form
Asprin in Powder Form
Intestine produces lactase
Intestine does notproduce lactase
November 30, 2011
4.3 Factors Affecting the Rate of Chemical Reations
Hydrogen Peroxide catalyst demo
H2O2 --> H20 + O2(g)
This happens very very slowly unless a catalyst is added:
- Sunlight can be a catalyst
- Manganese (IV) Oxide MnO2(s)- Liver Enzymes
Scientific MethodMorgan enjoyed making film canister rockets so much in Mr. Korotash's Science class that he took it up as a hobby. He spends a Saturday afternoon trying to perfect the technique so that the film canister goes as high as it possibly can.
What are some different techniques Morgan can try? What can he change about his setup to try and maximize the height?
All good scientific experiments have clear manipulated and responding variables. The researcher must also control other factors to make sure they don't influence the results.
Manipulated Variable: what is being changed about the experiment
Responding Variable: what is being measured, observed, recorded (results)
Controls: Aspects of the experiment that are purposely kept constant so as not to affect the results.
November 30, 2011
Scientific MethodMorgan decides to see what the optimal amount of water is to make the film canister go the highest. He decides to try it with 5 mL, 7.5 mL, 10 mL, 12.5 mL, 15 mL, 17.5 mL, and 20 mL.
For each test he uses the same film canister and only uses one alka-seltzer tablet. Also the temperature of the water is the same. He does not shake any of the canisters.
Morgan places a measuring tape on the wall and visual estimates the height that the canister flies.
What is the manipulated variable?
What is the responding variable?
List as many controls as you can.
If Morgan graphed his results, what kind of graph should he use? Which axes do the variables go on?