Chemistry 101 Dr. Don DeCoste 3014 Chemistry Annex decoste@illinois.edu 2-3 pm Mondays and 10-11 am Thursdays By appointment Open door policy

To Do… Chapter 8 this week. OWL Textbook homework OWL Chapter 5 due Friday (1/26) by 10 pm. Chapter 8 due Tuesday (1/30) by 10 pm. Lab write-up due in Discussion tomorrow.

Clicker Question You have a 10.0 g sample of copper (Cu). What mass of magnesium (Mg) do you need to have the same number of Mg atoms as Cu atoms? a) More than 10.0 g of Mg. b) Less than 10.0 g of Mg. c) 10.0 g of Mg. d) I have no idea.

Calculate… You have a 10.0 g sample of copper (Cu). Determine the mass of magnesium (Mg) such that the number of copper atoms and magnesium atoms are equal.

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?

Consider This… Does a methane molecule (CH4) contain more hydrogen or more carbon?

Calculate… Determine the percent mass of oxygen in each of the following substances: H2O (water) H2O2 (hydrogen peroxide)

Calculate… You have 100.0 g samples of each of the following compounds: Sulfuric acid: H2SO4 Sucrose (table sugar): C12H22O11 Potassium chlorate: KClO3 Which one has the greatest number of oxygen atoms?