Chemistry 202 Dr. Don DeCoste 367J Noyes Lab 11am-12pm Mondays and Wednesdays (after lecture) am Tuesdays and 1-2 pm Thursdays By appointment; open door policy 1

Lon-Capa 1 st HW assignment due Friday, 9/4, 5 pm. It is open now. 1 st Quiz due Sunday, 9/6 by 10 pm. It will open Wednesday, 9/1 at 5 pm. 2

For Friday Begin/continue working on Lon-Capa. Continue reading Chapter 3 and doing the Chapter 3 homework (Challenge Problems!). See me or me if there are any questions or concerns. 3

Using The Periodic Table 4

Table 2-3 p37 5

Table 2-4 p38 6

Table 2-5 p39 7

Table 2-6 p40 8

9 Three Big Topics Stoichiometry: information on “what” happens; allows us to determine amounts of reactants and products. Thermodynamics: information on “why” reactions happen; allows us to make predictions about whether a reaction will occur. Kinetics: information on “how” reactions happen (mechanisms); relates to the speed of reactions.

10 Three Big Themes Content: specific topics in chemistry. Models: a way of explaining the phenomena we observe; theories. Understand significance and limitations. Problem Solving: be able to solve novel problems in a creative and flexible way using conceptual understanding of fundamental ideas; Challenge Problems in the text are good for this.

A Question for You… Estimate the number of atoms in an adult human. 11

Clicker Question The number of atoms in an adult human is: a) Much less than b) Right around c) Much greater than

13 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? Diagrams and more questions can be useful.

Big Ideas of Mole Concept  We can count by weighing (relative masses).  Reactions occur by number of particles, we often deal with masses. [We will deal with gases and solutions as well] 14

Chemical Reaction 15

Average Atomic Mass? 16

Calculate… Determine the percent mass of oxygen in each of the following substances H 2 O (water) H 2 O 2 (hydrogen peroxide) 17