Office Hours 367J Noyes Lab decoste@illinois.edu 11am-12pm Mondays and Wednesdays (after lecture) 10-11 am Tuesdays and 1-2 pm Thursdays By appointment; open-door policy

“My First Chemistry Exam Did Not Go Well, Now What?” Come join us for a discussion on how to improve your exam scores! We will chat about the differences between high school and college chemistry classes, study skills moving forward, and time management. Taught by Dr. Christian Ray (General Chemistry Director) Tuesday, October 4th, 4:00-5:20pm, 162 Noyes Lab

Don’t forget textbook homework! Lon-Capa 4th HW assignment due Friday, 10/7, 5 pm. It is open now. 3rd Quiz due Sunday, 10/9 by 10 pm. It will open Friday, 10/7 at 5 pm. 5th assignment is open as well (Chapter 10) Don’t forget textbook homework!

The Piston, Moving a Distance Against a Pressure P, Does Work On the Surroundings

Determining Hrxn Since H = qp, determine the heat given off or required at constant pressure by measuring temperatures. This is termed calorimetry. Since energy is conserved, we can often determine Hrxn for one reaction given values of Hrxn for others. Uses the principle in Hess’s Law. Use standard enthalpies of formations for reactants and products (we have tables of these).

A Coffee-Cup Calorimeter Made of Two Styrofoam Cups

Specific Heat Capacities

Clicker Question You drop 50.0 g of 100.0C metal into 100.0 g of 22.0C water. The final temperature of the water is 29.5C. Identify the metal. c(water) = 4.18 J/g C a) aluminum (c=0.89 J/gC) b) iron (c=0.45 J/gC) c) copper (c=0.39 J/gC) d) lead (c=0.13 J/gC) e) I do not know how to do this.

Constant-Pressure Calorimetry Can determine enthalpy change for chemical reactions that occur in solution. See Example 9.3 on pages 315-317 of your text. Can calculate ΔE and ΔH when PV work occurs. See Example 9.4 on pages 317-318 of your text.

Bomb Calorimeter (constant V) Can calculate ΔE for a chemical reaction. See Example 9.5 on page 320 of your text.