1. Welcome to AP Chemistry

2. What is AP Chemistry? It is several things
Equivalent of a 1st year college inorganic chemistry class
A class that will prepare you for a test
Early May
Hard work
A wonderful way to start the day !
Now on to the details

3. Rules and Procedures
You know the basic rules but here are a few that are specific for this class.
No food, drink, or gum
Don’t disrupt. Be respectful of all.
Be ready to start when class begins.
Refer to the Course Guidelines sheet found on the website and handed out to you.
The class website is

4. Rules and Procedures
You are AP ! I will treat you as such as long as you act accordingly.
There are resources that it would help to be familiar with.
Quizlet
Khan Academy or similar
More to follow

5. Rules and Procedures
LAB – Because of the importance of safety in the lab, violation of laboratory safety rules and procedures may result in loss of lab privileges.
LAB SAFETY (otherwise known as OUR SAFETY) is not taken lightly.

6. Significant figures Meaningful digits in a MEASUREMENT
Exact numbers are counted, have unlimited significant figures
If it is measured or estimated, it has significant figures.
If not, it is exact.
All numbers except zero are significant.
Some zeros are, some aren’t

7. Which zeroes count ?
In between other significant figures, they DO COUNT
Before the first number, they DON’T COUNT
After the last non-zero number counts IF it is after the decimal point. (see below)
significant figures
significant figures

8. Doing the math
Multiplication and division, same number of significant figures in answer as the least number in the problem.
Addition and subtraction, same number of decimal places in answer as least number in the problem.

9. Scientific Method Metric System Uncertainty
More Preliminaries
Scientific Method
Metric System
Uncertainty

10. Scientific method A way of solving problems
Observation - What is seen or measured
Hypothesis - Educated guess of why things behave the way they do. (a possible explanation)
Experiment- Designed to test hypothesis
Leads to new observations, and the cycle goes on.
See the PPT on the website for more detail.

11. Scientific method.
After many cycles, a broad, general explanation is developed for why things behave the way they do.
Theory - Regular patterns of how things behave the same in different systems emerges
Law - Laws are essentially theories that have been proven beyond reasonable doubt.

12. Scientific method. Theories have predictive value.
The true test of a theory is if it can predict new behaviors.
If the prediction is wrong, the theory must be changed.
A key to the Scientific Method is that a Theory is constantly evolving due to more and more experimentation.

13. Law Observations Theory (Model) Hypothesis Modify Experiment
Prediction
Law
Experiment

14. Metric System Every measurement has two parts Number Scale (unit)
SI system (le Systeme International) based on the metric system
Prefix + base unit
Prefix tells you the power of 10 to multiply by - decimal system - easy conversions

15. Metric System Base Units Mass - kilogram (kg) Length- meter (m)
Time - second (s)
Temperature- Kelvin (K)
Electric current- ampere (amp, A)
Amount of substance- mole (mol)
While not a base unit, the Liter (L) is commonly seen.

16. Commonly Used Prefixes
Giga - G 1,000,000,
Mega - M 1,000,
Kilo - k 1,
Deci - d
Centi - c
Milli - m
Micro - m
Nano - n

17. Deriving the Liter Liter is defined as the volume of 1 dm3
A milliliter is the volume of 1 cm3

18. Mass and Weight
Mass is measure of resistance to change in motion, measured in grams.
Weight is force of gravity.
Sometimes used interchangeably, which while technically isn’t correct is usually fine since the problems are always done at earth’s gravity.
Mass can’t change, weight can

19. Uncertainty Basis for significant figures
All measurements are uncertain to some degree
Precision - how repeatable
Accuracy - how correct - closeness to true value.
Random error - equal chance of being high or low - addressed by averaging measurements - expected

20. Uncertainty Systematic error - Same direction of error each time
Better precision implies better accuracy
You can have precision without accuracy
You can’t have accuracy without precision

21. Using the units to solve problems
Dimensional Analysis
Using the units to solve problems

22. Dimensional Analysis Use conversion factors to change the units
1 foot = 12 inches (equivalence statement)
12 in = = 1 ft ft in
2 conversion factors
multiply by the one that will give you the correct units in your answer.

23. Examples 11 yards = 2 rod 40 rods = 1 furlong 8 furlongs = 1 mile
The Kentucky Derby race is 1.25 miles. How long is the race in rods, furlongs, meters, and kilometers?
A marathon race is 26 miles, 385 yards. What is this distance in rods, furlongs, meters, and kilometers?

24. Examples
Science fiction often uses nautical analogies to describe space travel. If the starship U.S.S. Enterprise is traveling at warp factor 1.71, what is its speed in knots?
Warp 1.71 = 5.00 times the speed of light
speed of light = 3.00 x 108 m/s
1 knot = 2000 yd/h exactly

25. Examples
Apothecaries (druggists) use the following set of measures in the English system:
20 grains ap = 1 scruple (exact)
3 scruples = 1 dram ap (exact)
8 dram ap = 1 oz. ap (exact)
1 dram ap = g
1 oz. ap = ? oz. troy
What is the mass of 1 scruple in grams?

26. Examples
The speed of light is 3.00 x 108 m/s. How far will a beam of light travel in 1.00 ns?

27. Temperature and Density

28. Temperature
A measure of the average kinetic energy of the particles of a sample.
While we might occasionally refer to °F, in this class we will be using °C and Kelvin
Kelvin can easily be converted to °C by the following: °C = K
Note that Kelvin doesn’t have a degree sign.

29. Density Ratio of mass to volume Density = mass / volume OR D = m / v
Useful for identifying a compound
Useful for predicting weight
An intensive property - does not depend on what the amount of material is.

30. Density Problem # 1
An empty container weighs g. filled with Carbon Tetrachloride (density 1.53 g / ml ). The container weighs g. What is the volume of the Carbon Tetrachloride ?

31. Density Problem # 1 answer
An empty container weighs g. filled with Carbon Tetrachloride (density 1.53 g / ml ). The container weighs g. What is the volume of the Carbon Tetrachloride ?
Step 1: List the given info
Mass of Container = grams
Density of Carbon Tetrachloride = 1.53 g / mL
Mass of both = grams
Volume of Carbon Tetrachloride = ?
Step 2: Write down the formula
Density = Mass/Volume (D = m/V)

32. Density Problem # 1 answer
Step 3: Substitute
1.53 = mass / VOLUME
We need the mass: – = grams
1.53 = / Volume
Step 4: Solve Volume = mL

33. Density Problem # 2
A 55.0 gallon drum (barrel) weighs 75.0 lbs when empty. What will the total mass be when filled with ethanol (in pounds) ? density of ethanol = g / mL
1 gallon = 3.78 L 1 lb = 454 g

34. Density Problem # 2 answer
For properties such as Density, it is quite common to use it as a way to get to another value.
So in this problem, we are using more problem solving techniques, such as unit analysis.

35. Density Problem # 2 answer
Step 1: Determine the volume of the drum in mL, which equals the volume of ethanol.
55 x 3.78 = L  207,900 mL
Step 2: Determine the mass of ethanol.
.789 = mass / 207,900 mass = 164,033.1 g

36. Density Problem # 2 answer
Step 3: Convert grams of ethanol to lbs.
164,033.1 / 454  lbs of ethanol
Step 4: Add the mass of the ethanol to the mass of the drum
lbs + 75 lbs (drum) = lbs
NOTE: We will not be using lbs in class.

37. Classification of Matter
There are three states of matter that we are primarily interested in:
Solid Liquid Gas
Solid: Definite Shape & Definite Volume
Liquid: Indefinite Shape & Definite Volume
Gas: Indefinite Shape & Indefinite Volume

38. Classification of Matter
Lots of Vocabulary Words here
Mixture: Composed of different parts that are making up one substance.
Homogeneous – Equal composition throughout
Heterogeneous – Varying composition
A homogeneous mixture is called a solution.

39. Classification of Matter
Pure Substance: Has a constant composition, such as water. All elements or compounds are Pure Substances.

40. Classification of Matter
Physical v. Chemical Changes
A physical change doesn’t change the composition of the actual chemical structure of the material.
Examples of physical changes:
Boiling water
Cutting a piece of paper

41. Classification of Matter
Physical v. Chemical Changes
A Chemical change does change the composition of the actual chemical structure of the material.
Exam ples of physical changes
Burning a material
Undergoing a chemical reaction (rxn).

42. Classification of Matter
Separation Techniques
Distillation: Using differences in Boiling Points to separate liquids.
Saltwater is distilled to obtain fresh water
Filtration: Using particle size to separate components
Coffee filters work on this principle.

43. Classification of Matter
Chromatography
A separatory technique that uses different different solubilities of materials to separate a liquid or a gas from a solid.
This is more often used for chemical analysis than for everyday use.

44. Classification of Matter
Four words in Chemistry that are important to keep organized are:
Atom, Molecule, Element, & Compound
Element: A single type of material, that can’t be broken down. There are 92 naturally occuring elements and 118 overall.
Examples: Lead, Oxygen, and Gold

45. Classification of Matter
Compound: A substance that is created from a combination of elements. There are about 50 million compounds and the list is growing every day.
Examples: Water, salt, and gasoline.

46. Classification of Matter
Atom: An atom is the smallest bit of an element that still has the properties of that element.
Molecule: A molecule is the smallest bit of a compound that still has the properties of that compound.