Welcome to AP Chemistry What is AP Chemistry

Welcome to AP Chemistry

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 – May 17 • Hard work • A wonderful way to start the day • Now on to the details

Rules and Procedures • You know the basic rules but here 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.

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.

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.

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.

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.

Grading • Percentage scale 94 -100% A 90 -94% A 87 -90% B+ 84 -87% B 80 -84% B 75 -80% C+ 70 -75% 65 -70% 62 -65% 58 -62% 55 -58% 0 -54% C CD+ D DF

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

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.

What you need for class • • Paper Pencil or pen, Calculator- scientific Book? – Not unless I let you know • Lab Notebook

Internet Ready • http: //mrgreen. tierranet. com • My email is tvgreen@aol. com

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

Any questions? • Lets get started

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

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 is written in 3200 2 sig figs • 3200. 4 sig figs

Doing the math • Multiplication and division, same number of sig figs in answer as the least in the problem • Addition and subtraction, same number of decimal places in answer as least in problem.

More Preliminaries Scientific Method Metric System Uncertainty

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

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 • Laws are summaries of observations

Scientific method. • Theories have predictive value. • The true test of a theory is if it can predict new behaviors. • If the prediction is wrong, theory must be changed. • Theory- why • Law - how

Observations Hypothesis Theory (Model) Modify Experiment Prediction Law Experiment

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

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)

• • gigamega kilo decicentimillimicronano- G M k d c m m n Prefixes 1, 000, 000 1, 000 0. 1 0. 001 0. 000000001 109 106 103 10 -1 10 -2 10 -3 10 -6 10 -9

Deriving the Liter 3 • Liter is defined as the volume of 1 dm 3 • gram is the mass of 1 cm

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

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

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

Dimensional Analysis Using the units to solve problems

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

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?

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

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 = 3. 888 g • 1 oz. ap = ? oz. troy • What is the mass of 1 scruple in grams?

Examples • The speed of light is 3. 00 x 108 m/s. How far will a beam of light travel in 1. 00 ns?

Temperature and Density

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

0ºC = 32ºF 0ºC 32ºF

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

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

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

(0, 32)= (C 1, F 1) ºF ºC

(0, 32) = (C 1, F 1) (120, 212) = (C 2, F 2) ºF ºC

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

Density Problem • An empty container weighs 121. 3 g. Filled with carbon tetrachloride (density 1. 53 g/cm 3 ) the container weighs 283. 2 g. What is the volume of the container?

Density Problem • A 55. 0 gal drum weighs 75. 0 lbs. when empty. What will the total mass be when filled with ethanol? density 0. 789 g/cm 3 gal = 3. 78 L 454 g 1 1 lb =