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 in May Hard work A wonderful way to start the day Now on to the details

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

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 70-75% C 90-94% A- 65-70% C- 87-90% B+ 62-65% D+ 84-87% B 58-62% D 80-84% B- 55-58% D- 75-80% C+ 0-54% F

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

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 Lab Notebook

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

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 the decimal point is written in 3200 2 sig figs 3200. 4 sig figs

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.

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 Law 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, the theory must be changed. Theory- why Law - how

Law Observations Theory (Model) Hypothesis 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)

Prefixes giga- G 1,000,000,000 109 mega - M 1,000,000 106 kilo - k 1,000 103 deci- d 0.1 10-1 centi- c 0.01 10-2 milli- m 0.001 10-3 micro- m 0.000001 10-6 nano- n 0.000000001 10-9

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

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 1 foot = 12 inches (equivalence statement) 12 in = 1 = 1 ft. 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 32ºF 0ºC

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

ºF ºC

(0,32)= (C1,F1) ºF ºC

(0,32) = (C1,F1) (120,212) = (C2,F2) 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/cm3 ) 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/cm3 1 gal = 3.78 L 1 lb = 454 g