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
Physical PropertiesColourLustreMelting & Boiling PointsHardnessMalleabilityDuctilityCrystal ShapeSolubilityDensityConductivity
Chemical PropertiesReaction with acidsReaction with basesBehaviour in airAbility to burnReaction to heat
What are physical & chemical properties of gold?
November 30, 2011
1.2 Organizing Matter
p.96 #2, 3, 5, 6p.104 #6, 7
1.2 Organizing Matter
All matter can be classified as either "pure" or as a mixture
Pure
Elements
Mixtures
CompoundsBasic building blocks, have their own symbol, listed in periodic table.
Ex. C, H, O, N
Two or more elements that are combined chemically.
Ex. H2O, CO2
Mechanical
Solutions Suspensions
ColloidsMore than one substance is visible
Ex. potting soil, salsa
One or more compounds dissolved in another - appears to be one substance
Ex. coffee, vinegar
A cloudy mixture that can be separated out or form sediments
Ex. muddy water, paint, tomato juice
Similar to a suspension, but microscopic (don't sediment, hard to separated)
Ex. Milk
November 30, 2011
1.2 Organizing Matter
Pure Mixtures
Elements Compounds Mechanical Solutions Suspensions Colloids
algae-filledwater
salt water
sterling silver(copper dissolved in silver)
LimestoneCaCO3
oxygen(O2)
1.2 Organizing Matter
p.104 #3-5, 8, 9
November 30, 2011
1.3 Observing Changes in Matter
Changes in matter can by either physical or chemical:
A physical change is when matter changes from one state to another (ex. ice to water)
A chemical change is when two or more materials react to produce new materials (ex. H20 + CO2 --> C6H12O6 + O2
1.3 Observing Changes in Matter
Evidence of Chemical Change:
1. Change in colour
2. Change in odour
3. Formation of a solid or gas
4. Release or Absorption of Heat Energy
November 30, 2011
1.3 Observing Changes in Matter
You decide... which of the following demonstrations show a physical reaction and which are chemical reactions?
Homework: p.109 #1-7
2.1 Evolving Theories of Matter
Create a time line that shows the key ideas in this chapter (p.113-120)
Start at 8000 B.C.
Point form is fine
Sketch atomic models that developed after 1800
November 30, 2011
2.1 Evolving Theories of Matter
Chem
ists
can
sta
rt a
nd c
ontr
ol f
ire
Met
als
had
not
been
dis
cove
red.
8000 B.C. 6000 B.C.
Gold
Dis
cove
red
4000 B.C. 2000 B.C.
Copp
er D
isco
vere
d
Silv
er D
isco
vere
d
Lead
Dis
cove
red
Tin
Dis
cove
red
(can
now
mak
e br
onze
wit
h Ti
n &
Copp
er
Iron
Dis
cove
red
Mer
cury
Dis
cove
red
Stone Age Iron Age
2.1 Evolving Theories of Matter
400 B.C. 350 B.C. 1597 A.D. 1660 A.D.0
Democritus Aristotle Alchemy Boyle
Atomos = indivisible Alchemy: Only a "pseudo-science"
- Focused on turning metals into gold- not interested in understanding nature of matter- made some contributions to science
Robert Boyle, a devoted scientist, believed the purpose of chemistry was to determine the types of particles making up each substance
November 30, 2011
2.1 Evolving Theories of Matter
1780 1808 1908 19221897Lavoisier Dalton Thomson Rutherford Bohr
2.1 Evolving Theories of Matter
Homework: Page 121 #3, 7, 8, 10
November 30, 2011
2.2 Organizing the Elements
Read pages 122-125 and answer questions p.125 #1-7
2.3 The Periodic Table Today
InteractiveP Table
What kind of basic information about the elements can be found in most periodic tables?
November 30, 2011
2.3 The Periodic Table TodayInteractiveP TableA. Element Symbol & Name
- symbol usually first letter of latin or english name- sometimes named after location or scientist
Using your periodic table, find the symbols and names of the following elements:
Name Symbol
Calcium
Fluorine
Gold
Curium
P
Fe
K
2.3 The Periodic Table Today InteractiveP Table
B. Atomic Number- The number in the upper left is the atomic number and it represents the number of protons (+ charge)
- Because atoms are neutral, the number of protons (+) equals the number of electrons (- charge)
Using your periodic table, complete the following table:Name Number of Electrons
Copper (Cu)
Tin (Sn)
12
Ne
Lead (Pb)
Number of Protons
94
25
November 30, 2011
2.3 The Periodic Table TodayInteractiveP TableC. Atomic Mass
- The mass of an atom is made up of the mass of protons + the mass of neutrons (electrons have very little mass)
- Atoms of the same element can sometimes have different numbers of neutrons. These are called isotopes.
- The mass number is equal to the number of protons + neutrons (not shown on periodic table)
- The number shown on the periodic table is the average of all isotopes and is called the atomic mass unit or average atomic mass
Mass Number:
2.3 The Periodic Table TodayInteractiveP TableC. Atomic Mass
Name # of Neutrons
Carbon (C) 6 12 6 6
# of ProtonsAtomic Number Mass Number
Carbon (C) 13
Carbon (C) 14
Vanadium (V) 51
Nickel (Ni) 58
Finish the table with 2 or 3 elements from the list at the bottom of page 129
November 30, 2011
2.3 The Periodic Table TodayInteractiveP TableD. Chemical & Physical Properties
Metals: Shiny, malleable, ductile, conduct electricity
Non-Metals: Solid or gas, dull, brittle, insulators which mean they do not conduct electricity (except carbon)
Metalloids: Metallic and non-metallic properties
2.3 The Periodic Table TodayInteractiveP TableD. Chemical & Physical Properties
- The periodic table is divided into groups (columns) and periods (rows)
11
3 4 5...
1234567
November 30, 2011
2.3 The Periodic Table Today
InteractiveP TableD. Chemical & Physical Properties
- The groups have similar properties:
Group 1: Alkali Metals: most reactive, react when exposed to air or water. Reactivity increase as you move down the group (as the period increases.)
Who's ready to blow something up?
Group 2: Alkaline-earth Metals: less reactive than alkali metals
Group 17: Halogens: most reactive non-metals and are easily combined with other elements
Group 18: Noble Gases: most unreactive elements
MetalsMovie
2.3 The Periodic Table Today
InteractiveP Table
Homework: page 134
# 1-7, 9
November 30, 2011
3.1 Naming Chemical Compounds
Boot
Chaps
Elk
Fanny
Homely
Kebab
What do these words mean?
3.1 Naming Chemical Compounds
Nomenclature is the science of naming chemical compounds.
Chemical compounds can be referred to by their common name(s), their scientific name, or by their chemical formula.
Common Name(s) Scientific Name Chemical Formula
Salt Sodium Chloride NaCl
Water Dihydrogen Monoxide H2O
Hydrochloric Acid Hydrogen chloride HClMuriatic Acid
November 30, 2011
3.1 Naming Chemical Compounds
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)
Let's start with the boring stuff: definitions...
4.1 Chemical Reactions
C6H8O7(aq) + 3NaHCO3(aq) --> 3H2O(l) + 3CO2(g) + Na3C6H5O7(aq)
Citric Acid Sodium Bicarbonate Water Carbon Dioxide Sodium Citrate
What are the reactants?
What are the products?
Is it endo or exothermic?
November 30, 2011
4.1 Chemical Reactions
FeCl3(aq) + NaOH(aq) --> Fe(OH)3(s) + NaCl(aq)Iron (III) Chloride Sodium Hydroxide Iron (III) Hydroxide Sodium Chloride
What are the reactants?
What are the products?
Is it endo or exothermic?
4.1 Chemical Reactions
Mg(s) + H2SO4(aq) --> MgSO4(aq) + H2(g)Magnesium and Sulfuric Acid produce Magnesium sulfate and Hydrogen gas
What are the reactants?
What are the products?
Is it endo or exothermic?
November 30, 2011
4.1 Chemical Reactions
CH3COOH(aq) + NaHCO3(s) --> CH3COONa(aq) + H2CO3(s)
H2CO3(aq) --> H2O(l) + CO2(g)
Acetic Acid (Vinegar) Sodium Carbonate Sodium Acetate Carbonic Acid (Baking Soda)
What are the reactants?
What are the products?
Is it endo or exothermic?
Carbonic Acid Water Carbon Dioxide
4.1 Chemical Reactions
Chemical Changes involving oxygen:
Combustion: and exothermic reaction of oxygen with some fuel to produce carbon dioxide and water vapour
Corrosion: a slow chemical change that occurs when oxygen reacts with metal (ex. rust)
Cellular respiration: oxygen is used to help convert some food (glucose) into carbon dioxide, water, and energy that our bodies can use
And now for more boring stuff...
November 30, 2011
4.1 Chemical Reactions
Homework: p.162 #1-9
4.2 Conservation of mass in Chemical Reactions
200g
100g5g
What will the total mass be after the vinegar and baking soda are mixed together?
305g?
More? Less?
What if we cover the beaker?
CH3COOH(aq) + NaHCO3(s) --> CH3COONa(aq) + H2O(l) + CO2(g)
November 30, 2011
4.2 Conservation of mass in Chemical Reactions
Read the lab on page 164
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?