Welcome! (Sept 7) Out on desk and ready for quiz: Calculator, Pencil NOT on your desk or out at all: Phones (OFF and AWAY always!) Food, gum, drinks (except water) Laptop

Molarity quiz! (25 min) Let’s see what you can do! If finished early, come give me the quiz and get a syllabus to start reading!

Procedure Reminders! If you were absent, where would you look for the papers you missed? Where do we turn in HW or labs? Where are extra supplies (paper, stapler, rulers, hole punch?) What should you do if you were absent?

Syllabus and Whoops Passes If you lose your whoops passes, you lose your privilege! Read through syllabus and safety contract CAREFULLY this weekend. EVERY WORD! Get a lab book this weekend – you need it in class Monday

The AP TEST – What is it? Monday, May 7th – Time is short! TOUGH, INTEGRATED PROBLEMS! Multi-part, LOTS of explanation What you get: Periodic Table (no names) TWO pages of constants and equations (on both) What you don’t get: Calculators on multiple choice!

From Adrian Dingle

AP TEST closer look Part 1: Multiple Choice Questions 90 minutes 50-60 questions! No calculator PT and equations sheets 50% of score Part 2: Free Response Questions 105 minutes 7 questions (4 long, 3 shorter) Calculator

Old AP Chem Exam (1961 - 2013) (question from 1999 exam) Old test VERY math heavy, still some explanation, but very low amount

New AP Chem Exam (2014 – Present) (question from 2016 exam) AP Chem test now highly prioritizes scientific thinking, and ability to explain and draw diagrams to show understanding. In addition, scientific thinking requires the ability to explain and extend, so these are great skills to learn for all!

AP Grade Breakdown (approx.) 1 : 0 – 26% 2 : 27 – 41% 3 : 42 – 57% 4 : 58 – 71% 5 : 72 – 100% 2014 grade breakdown for new syllabus – this is our best estimate, even though only N=1

AP Chem Exam Results

Okay, let’s dive in! In our book, Zumdahl: Chapter 1: Scientific Measurement (sig figs), Density Chapter 2: Atomic Theory, Ions, Periodic Table, Element Names and States, Naming compounds Chapter 3: Moles, Empirical Formula, Stoichiometry, Molar Mass, Balancing, Limiting Reagent We will not review Ch.1-3 in class – this is assumed knowledge from Year 1 You will review again during winter break Coming soon: Unit 1 Test  Chapters 1-3 and molarity (Ch 4) I’ll always try to give “AP Style questions”

Gravimetric Analysis Gravimetric analysis = An analytical method to determine components of a mixture (solution or solids) quantitatively. Generally involves one or more chemical reactions Also could be to analyze for an unknown and identify it by molar mass Finding a way to analyze one component by mass in a mixture (solid or liquid). Usually through precipitation

Gravimetric Example Consider a mixture of AgNO3 and NaNO3. Your goal is to find the grams of each component in the mixture. How could you react (precipitate) one component but not the other? What would you do after that?

Gravimetric Example, cont’d If a sample of AgNO3 and NaNO3 has a total starting mass of 4.50 grams and excess aqueous NaCl is used to precipitate out all of the silver ions, yielding 2.25 grams of AgCl (s), what was the percent by mass of each component in the original sample? 58.4% AgNO3 Also could use to determine amount of vitamin C in orange juice, etc…

Lab #1 Wednesday in class and after school Safety Training Reminders Gravimetric Lab NOTE: I have a release day with the science department on Monday, so you’ll have a sub  BRING YOUR LAPTOPS and headphones Webassign login and assignment #1: Molarity, Stoich, Gravimetric, Review Lab 1 Pre-lab and procedure due in class Wednesday

Homework Day 2 One practice gravimetric problem due for next class: Ch 3: 144 Review on your own as needed: Chapter 1-3 Syllabus signature page due Monday! Make sure you AND parent/guardian have read completely and signed the last page Get a lab book this weekend – you need it for Monday class Lab #1 after school Wednesday - requirement