Welcome to AP Chemistry Pick up the handouts on the front desk Find your seat Using your laptop or phone, please fill out the google form here: bit.ly/welchem When done, introduce yourself to the person next to you Today: Syllabus and Safety Overview Chemistry Fundamentals Review

Important Dates Return Safety Contract ASAP Quiz TOMORROW: Common Elements and Ions Unit 1 MC Packet due Wed 9/12

Syllabus Overview

Syllabus Overview

Syllabus Overview

Safety Video https://www.youtube.com/watch?v=xJG0ir 9nDtc

Safety Contracts Return (signed by you and a parent or advisor) by Mon 9/3

Is AP Chem really that hard? Yes. I will do my best to organize the information in a meaningful way for you all and for you guys to practice problems as much as possible in class Even so, this will require you to spend some time outside of class to really try to digest and understand the content. Note: more difficult content = we get to look at some more cool stuff/reactions as well.

Unit 1 Packet All multiple choice questions covering essential content from Chem 1 Due 9/12 If you need help on these questions, arrange to come see me during help session

Common Elements and Ions: You have a quiz on this tomorrow!

Units and Sig Figs Yes, they’re silly and annoying, but there are FRQs where you get a point just for having the correct units and sig figs so let’s try to get those easy points, k?

Common Units: know the symbols! Know what each is used for! Measurement meter m  length/distance gram g  mass grams/milliliter grams/centimeter3 g/mL g/cm3   density moles mol   amount (of a chemical) Molarity M  concentration Kelvin  K  temperature second  s  time Joule  J  energy Hertz (or sec-1 or 1/sec)  Hz (s-1, 1/s)  frequency kilopascals, atmospheres, millimeters of Mercury  kPa, atm, mm Hg   pressure

Measurement: When using tools with graduated “tick marks”, you should estimate one decimal place beyond the value of the smallest tick mark! 0.7 cm Each tick mark represents 1 cm  round to nearest 0.1 cm

Each tick mark represents 0.1 cm  round to nearest 0.01 cm

Reading Graduated Cylinders: Liquids form a curved surface when in graduated cylinders. As a standard, you should read the liquid level from the bottom of the meniscus

The Concept of Error With each measurement, there is a degree of uncertainty/estimation beyond the markings The last digit in a measurement is called the uncertain digit Significant figures include all measured digits + the uncertain digit The more significant figures, the more precise the measurement

Rules for Counting Significant Figures Non-zero digits ALWAYS count as significant figures Ex: 2371 Zeroes between non-zero digits (“sandwiched zeroes) are ALWAYS significant Ex: 105 all non-zero numbers are significant 4 sig figs 3 sig figs all non-zero numbers are significant Sandwiched zeroes are significant

Rules for Counting Significant Figures Zeroes to the left of the first non-zero digit are not significant Ex: 0.0035   2 sig figs All nonzero numbers are significant Zeroes to the left of “3” (the first nonzero digit) are placeholders, not significant (this is true every time so I’m going to stop writing it)

Rules for Counting Significant Figures Zeroes to the right of the last non-zero digit are only significant if there is a decimal point present. Ex 1: 1.080 Ex 2: 100,000 4 sig figs Sandwiched zeroes are significant Zeroes at the end are significant since decimal point is present 1 sig fig There’s no decimal point, so zeroes at the end are just placeholders and not significant

Shortcut: Pacific-Atlantic Rule Decimal point Present, start counting on the left (Pacific) side with the first non-zero digit Decimal point Absent, start counting on the right (Atlantic) side with the first non-zero digit

3 2 5 1 4

Calculations with Significant Figures When adding and subtracting, round the final answer to the same number of decimal places as the measurement with the fewest decimal places.

Calculations with Significant Figures When multiplying and dividing, round the final answer to the same number of significant figures as the measurement with the fewest significant figures.

Calculations with Significant Figures When performing calculations with multiple steps, carry as many numbers as possible throughout the calculations and only round off the final answer. Round the final answer off based on the last calculation performed.

14.9 180.3 0.619 1246 0.220