“i’m curious…”: generate a list of at least three things that you’re most curious about...
TRANSCRIPT
Warm-up
“I’m Curious…”: Generate a list of at least three things that
you’re most curious about in chemistry.
Review and Recall
The Study of Chemistry
Properties of Matter
Units of Measurement
Uncertainty in Measurement
Dimensional Analysis
The Study of Chemistry
Essential Question (E.Q.): Can I explain from my perspective what chemistry is about and why it is useful to learn chemistry?
The Study of Chemistry
Study of composition and behavior of matter.
Matter – Physical material of the universe. Has mass, occupies space, and created by elements.
Atom – Building block of matter.
Element – Basic particles created by atoms. 117 are currently known!
The Study of Chemistry
Every change in our observable world has its basis in the world of atoms.
We’ll speak in terms of two realms: Macroscopic (Macro = large) Submicroscopic ( Atoms, compounds, and
molecules.
“Coach Lightfoot…Why Study Chemistry???”
Understand how the world works Extremely practical! Public concern Environmental protection Food, clothing, and shelter Food production Understand how chemicals effect us
Chemistry – THE CENTRAL SCIENCE
Chemistry Put to Work…
Top Eight Chemicals Produced by the Chemical Industry
Rank
Chemical Formula
2006 Production
Principal Uses
1 Sulfuric Acid H2SO4 79B pounds Fertilizers
2 Ethylene C2H4 55B pounds Plastics, antifreeze
3 Lime CaO 45B pounds Paper, cement
4 Propylene C3H6 35B pounds Plastics
5 Phosphoric acid H3PO4 24B pounds Fertilizers, Coca-Cola
6 Ammonia NH3 23B pounds Fertilizers
7 Chlorine Cl2 23B pounds Bleaches, plastics
8 Sodium hydroxide
NaOH 18B pounds Aluminum production, soap
Household Chemicals
Baking Soda Borax Clorox™ Hydrogen Peroxide Pepto-Bismol™ Vinegar Windex™ Zerex™ (Antifreeze)
Sodium bicarbonate Sodium borate Sodium hypochlorite Hydrogen peroxide Bismuth subsilicate Acetic acid Acetic acid Ethylene glycol
Chemistry and Life!
Plants Respiration Plant Defense Seasonal Change
Animals Respiration Defense/Immunity Growth and reproduction
Take 2min. Try these with your neighbor!
Discuss what chemicals you’d like to learn more about.
*Explain from your perspective what chemistry is about and why its useful to learn chemistry.
Summary…
What is chemistry about? What is matter composed of? Where is chemistry useful?
See you Later!Study your notes!
Warm-Up
In a brief paragraph, opine how cooking and chemistry are alike.
Review and Recall
The Study of Chemistry
Properties of Matter
Units of Measurement
Uncertainty in Measurement
Dimensional Analysis
Properties of Matter
E.Q.: Can I identify and explain the different properties of matter?
Properties of Matter
Each substance has a unique set of properties.
These properties can be physical or chemical.
Physical Property – Physically observable properties (color, odor, density, melting point, boiling point, and hardness).
Chemical Property – Describes a substance by its identity (reactivity and flammability).
Properties of Matter
Observe the image...
With physical and chemical properties come physical and chemical changes!
Copper is red-brown, opaque, solid: physical properties.
Ethanol is flammable: a chemical property.
Physical and Chemical Changes
Physical Property – Changes physical appearance but not its chemical identity. Ex. Changes of state: boiling, freezing,
sublimation, etc.
Chemical Property – Changes a chemical identity. Ex. Chemical reactions
19
Key Terms: Properties
Physical change - No change in composition.
No new substances are formed. Ex. Evaporation; melting;
cutting wood; dissolving sugar in water.
Chemical change or chemical reaction - A change in composition.
New substances are formed. Ex. Burning gasoline;
dissolving metal in acid; spoilage of food.
The liquid fuel evaporates: a physical change.
The vapor burns, combining with oxygen: a chemical change.
Separation of Mixtures
Because each component of mixtures has its own properties, we can separate a mixture into its components. Three methods:
Chromatography
Distillation
Filtration
Take 2min. Try These!
Identify each as a physical or chemical change: Photosynthesis Water vapor in the air on a cold day forms frost.
Summary…
What are the properties of matter? What type of changes can matter undergo? What are the three types of separation
techniques?
See You Later!Study Your Notes!
Warm-Up
In a brief paragraph, explain everything you know about units of measurement.
Review and Recall
The Study of Chemistry
Properties of Matter
Units of Measurement
Uncertainty in Measurement
Dimensional Analysis
Units of Measurement
E.Q.: How do I explain the importance of accurate units of measurement in chemical and physical processes?
Units of Measurement
Many properties of matter are quantitative. Quantitative – Relating to NUMBERS!
When a number represents a measurement, its units must be specified.
The units used for scientific measurement are those of the metric system.
In 1960, an international agreement was reached to expressed a choice of metric units – SI Units.
SI Base Units
SI Base UnitsPhysical Quantity Name of Unit Abbreviation
Mass Kilogram kg
Length Meter m
Time Second s
Temperature Kelvin K
Amount of Substance Mole mol
Electric Current Ampere A
Luminous Intensity Candela cd
Metric Prefixes
Metric PrefixesPrefix Abbreviation Meaning Example
Tera T 1012 1 gigameter (Tm) = 1 x 1012 m
Giga G 109 1 gigameter (Gm) = 1 x 109 m
Mega M 106 1 megameter (Mm) = 1 x 106 m
Kilo K 103 1 kilometer (km) = 1 x 103 m
Deci d 10-1 1 decimeter = 1 x 10-1 m
Centi c 10-2 1 centimeter = 1 x 10-2 m
Milli m 10-3 1 millimeter = 1 x 10-3 m
Micro μ 10-6 1 micrometer = 1 x 10-6 m
Nano n 10-9 1 nanometer = 1 x 10-9 m
Pico p 10-12 1 picometer = 1 x 10-12 m
Fempto f 10-15 1 femptomenter = 1 x 10-15 m
Temperature
Measure of the hotness or coldness of an object.
Derived SI Units
Speed
Force
Pressure
Energy
Density…The only one that we’ll look at!
Volume
Burette
Syringe
Pipette
Graduated Cylinder
Volumetric Flask
Density
Property of matter defined as the amount of mass in a unit of volume of substance.
Usually expressed in grams per milliliter (g/mL).
More dense items sink; less dense float!
Chemistry in the News!!!
Biofuels
New element created (Element 118)
Antibiotic Modified to Combat Bacterial Resistance
The Hole Story (Ozone)
Take 2min. Try These!
Calculate the density of 18.0g of mercury occupying a volume of 100.0mL.
Indicate the SI units for mass, length, volume, and temperature.
Summary…
Units of Measurement…
Density…
See You Later!Study Your Notes!
Warm-Up
What is meant by the term “Uncertainty”?
Review and Recall
The Study of Chemistry
Properties of Matter
Units of Measurement
Uncertainty in Measurement
Dimensional Analysis
Uncertainty in Measurement
E.Q.: Can I realize the relationship between accuracy and precision?
Uncertainty in Measurement
Two types of numbers are encountered in scientific work:
Exact numbers (1 dozen = 12, 1.0m = 100cm)
Inexact numbers (Numbers obtained by measurement)
Which of the following is an exact number? Number of students in class OR mass of a penny
Precision and Accuracy
PRECISION
How closely many measurements agree with one another
ACCURACY
How closely many measurements agree with the “correct” value
Significant Figures (aka Sig Figs)
Uncertainties always exist in measurements.
These uncertainties are shown by significant figures.
Significant figures - All digits of a measured quantity.2.2g = 2 sig figs 5.46g = ______ sig figs
2.2405g = 5 sig figs 1.67g = ______sig figs
3 Rules for Sig Figs…
Zeros between nonzero digits are always significant – 1005kg (four); 1.03kg (three)
Zeros at the beginning of a number are never significant – 0.02L (one); 0.0026L (two)
Zeros at the end of a number are significant if number contains a decimal – 0.0200kg (three)
45
Significant Figures in Calculations
General: Base the number of digits in a result on the measurements and not on known values (such as atomic masses, accurately known densities, other physical constants, etc.)
Multiplication and division: Use the same number of sig figs in the result as the
data with the fewest sig figs. Addition and Subtraction:
Use the same number of decimal places in the result as the data with the fewest decimal places.
Significant Figure Fun!
WE GO LUNCH AT 11:42004332233AM!!!
I WEIGH 187.0004LBS!!!
Try These!
The width, length, and height of a small box are 15.5cm, 27.3cm, and 5.4cm. Calculate the volume of the box using correct sig figs!
10.5m x 100.00m = _________m2
(3.2 + 12.00)g = _________g
Summary…
Uncertainty in Measurements… Accuracy vs. Precision… Sig Figs…
See You Later!
Try these at home:
3.45g + 5.00g = _________g
100.5m - 10.00m = _________m2
2.30m x 5.00m = _________m2
100.00m2 / 10.00m = _________m2
Warm-Up
In your own words, define analysis.
Review and Recall
The Study of Chemistry
Properties of Matter
Units of Measurement
Uncertainty in Measurement
Dimensional Analysis
Dimensional Analysis
E.Q.: How is dimensional analysis used to solve scientific problems?
Dimensional Analysis
An aid in problem solving
Units “cancel out” to yield proper answers.
Dimensional Analysis
Try this! Take 2min...
If a woman has a mass of 115lb, calculate her mass in grams. (HINT: 1.0lb = 453.6g)
Two or More Conversion Factors
We also have conversion factor that convert from one measure to a different measure.
Try this! Take 2min...
The average speed of a nitrogen molecule in air is 515m/s. Convert this speed to miles per hour (mph). (1600m = 1.0mi)
Try this!
A car travels 28mi per gallon (mpg) of gasoline. Convert these unit to km per liter (km/L). (HINT: 3.8L = 1.0 gallon).
Try these!
Using your knowledge of metric units, convert the following: 0.076L to mL 0.05m to mm 5.0 days to seconds.
ACCELERATED: Try these also! Speed of light is 3.00 x 108m/s to miles per hour
(mph) 5.85gal/hr to liters per second (L/s)
Summary...
Dimensional analysis... Measurement conversions...
See You Later!Study your notes!