Chemistry 202 Dr. Don DeCoste 3014 Chemistry Annex decoste@illinois.edu 11am-12pm Mondays and Wednesdays (after lecture) 10-11 am Tuesdays and 1-2 pm Thursdays By appointment; open door policy

Lon-Capa 1st HW assignment due Friday, 9/6, 10 pm. It is open now. 1st Quiz due Sunday, 9/8 by 10 pm. It will open Friday, 9/6 at 5 pm.

For Today Textbook Homework Videos Chapter 3: Stoichiometry   Videos Chapter 3: Stoichiometry Problem Solving in Stoichiometry I: The Set-Up Problem Solving in Stoichiometry II: Method 1 Problem Solving in Stoichiometry III: Method 2 Problem Solving in Stoichiometry IV: Method 3

For Tuesday Textbook Homework Chapter 3: 63, 65, 112, 125, 126, 135, 140   The text homework is “two pages long” – OWL on page 1 and Discussion on page 2.

For Wednesday Textbook Homework Videos Chapter 3: Stoichiometry Challenge Problem: Chapter 3 #128 Chapter 4: Solution Stoichiometry Concentration and Dilution Precipitation Reactions and Solubility Rules

Chemistry Learning Center 2021 Chemistry Annex Chemistry TAs available from 9 am – 5pm Mondays – Fridays. Link to the schedule is on the website (Contact Information) Chemistry 202 TAs in the CLC: Tuesdays: 1-3pm: Bailey Wednesdays: 11am-1pm: Alex Thursdays: 3-5pm: Sydney

Clicker Question A metal ion has 23 electrons in an ionic compound that is about 30.% oxygen by mass. Which metal is in the oxide? a) Vanadium b) Chromium c) Manganese d) Iron e) I am not sure how to do this.  

Make Sure You Understand This… Determine the percent mass of oxygen in each of the following substances H2O (water) (88.81%) H2O2 (hydrogen peroxide) (94.07%)

Chemical Reaction

Clicker Question Balance the following equation in standard form and determine the sum of the coefficients: C2H5OH + O2 → CO2 + H2O a) 4 b) 5 c) 8 d) 9 e) 10

Problem Solving: A Journey Where Are We Going?: What are we trying to solve? What does this mean? Where Have We Been?: What do we know? What is given in the problem, and what is our knowledge base? How Do We Get There?: How do we connect what we know to what we are trying to solve?

Challenge Problem: Ch. 3