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Welcome to AP Chemistry

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Presentation on theme: "Welcome to AP Chemistry"— Presentation transcript:

1 Welcome to AP Chemistry

2 What is AP Chemistry? It is several things
Equivalent of 1 year college inorganic Chemistry class A class that will prepare you for a test in 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 LATE WORK If you forget to bring in your homework, I will accept it ONE day late with a parent's signature, for full credit. I will not accepted it any later

4 Rules and Procedures MAKE-UP WORK
It is your responsibility to make up all the work you missed. You have the same number of days that you were absent to turn in the missing work. Pick up any missing work, and notes before or after class. If you miss a test or quiz, it must be made up outside class.

5 Rules and Procedures TARDIES
You will be allowed one ”free" tardy per semester. The second and every subsequent tardy will result in a detention. Repeated tardies will result in parent contacts, and referrals, AND MAY RESULT IN BEING DROPPED FROM THE CLASS.

6 Rules and Procedures PASSES
Since every minute of class time is valuable, hall passes will be given only on an emergency basis, with a limit of one per semester, except under special circumstances.

7 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.

8 Grading Percentage scale 94-100% A 70-75% C 90-94% A- 65-70% C-
87-90% B % D+ 84-87% B % D 80-84% B % D- 75-80% C % F

9 Grading Lab Reports 15% Quarter Grade Tests 50% Homework/Classwork 20%
Quizzes 15% Lab Reports 15% Semester Grade 40% from each quarter 20% on final

10 Extra Credit Assignments will be provided approximately mid- quarter.
They may be turned in any time until the due date, (during the last week of the quarter) Extra credit may be used to raise the quarter grade by up to one letter grade. Extra credit is meant to be extra, so it will not be accepted if more than 10% of the other assignments are not turned in.

11 What You Need for Class Paper Pencil or pen, Calculator- scientific
Book Lab Notebook

12 Why First Period? College chemistry labs take more than 56 minutes,
To do those labs we will have to come early I will give you notice of when

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

14 Which zeroes count? In between other sig figs does
Before the first number doesn’t After the last number counts iff it is after the decimal point the decimal point is written in sig figs sig figs

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

16 More Preliminaries Scientific Method Metric System Uncertainty

17 Scientific method. A way of solving problems
Observation- what is seen or measured Hypothesis- educated guess of why things behave the way they do. (possible explanation) Experiment- designed to test hypothesis leads to new observations, and the cycle goes on

18 Scientific method. After many cycles, a broad, generalizable explanation is developed for why things behave the way they do Theory Also regular patterns of how things behave the same in different systems emerges Law Laws are summaries of observations

19 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. Theory- why Law - how

20 Law Observations Theory (Model) Hypothesis Modify Experiment
Prediction Law Experiment

21 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

22 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)

23 Prefixes giga- G 1,000,000,000 109 mega - M 1,000,000 106
kilo - k 1, deci- d centi- c milli- m micro- m nano- n

24 Deriving the Liter Liter is defined as the volume of 1 dm3
gram is the mass of 1 cm3

25 Mass and Weight Mass is measure of resistance to change in motion
Weight is force of gravity. Sometimes used interchangeably Mass can’t change, weight can

26 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

27 Uncertainty Systematic error- same direction each time
Want to avoid this Better precision implies better accuracy you can have precision without accuracy You can’t have accuracy without precision

28 Dimensional Analysis Using the units to solve problems

29 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.

30 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?

31 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

32 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?

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

34 Temperature and Density

35 Temperature A measure of the average kinetic energy
Different temperature scales, all are talking about the same height of mercury. Derive a equation for converting ºF toºC

36 0ºC = 32ºF 32ºF 0ºC

37 100ºC = 212ºF 0ºC = 32ºF 0ºC 100ºC 212ºF 32ºF

38 100ºC = 212ºF 0ºC = 32ºF 100ºC = 180ºF 0ºC 100ºC 212ºF 32ºF

39 100ºC = 212ºF 0ºC = 32ºF 100ºC = 180ºF 1ºC = (180/100)ºF 1ºC = 9/5ºF 0ºC 100ºC 212ºF 32ºF

40 ºF ºC

41 (0,32)= (C1,F1) ºF ºC

42 (0,32) = (C1,F1) (120,212) = (C2,F2) ºF ºC

43 Density Ratio of mass to volume D = m/V
Useful for identifying a compound Useful for predicting weight An intrinsic property- does not depend on what the material is

44 Density Problem An empty container weighs g. Filled with carbon tetrachloride (density 1.53 g/cm3 ) the container weighs g. What is the volume of the container?

45 Density Problem A 55.0 gal drum weighs 75.0 lbs. when empty. What will the total mass be when filled with ethanol? density g/cm3 1 gal = 3.78 L 1 lb = 454 g


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