Nov 16

Energy Changes Objectives

We are just starting on the Energy Changes unit. Here is a summary of what you are responsible for in this unit:

# Objective Must-do Activities Videos
1 Produces an energy diagram representing the energy balance for a chemical reaction Energy Diagram assignment, Energy Test #1 Energy Diagrams, Reversible Reactions
2 Interprets the energy diagram of a chemical reaction Energy Diagram assignment, Energy Test #1 Energy Diagrams, Reversible Reactions
3 Explains qualitatively the enthalpy change of substances during a chemical reaction Energy Test #1 Heat Transfer, Enthalpy, Energy Diagrams
4 Determines the molar heat of a reaction using a calorimeter Molar Heat assignment, Energy Test #1 Heat Transfer, Molar Heat,  Neutralization, Stoichiometry
5 Determines the molar heat of a reaction using Hess’s Law Hess’s Law assignment, Energy Test #2 Hess’s Law
6 Determines the molar heat of a reaction using bond enthalpes Bond Enthalpies assignment, Energy Test #2 Bonding Enthalpies

Oct 27

Yeast lab

Here is the chemical equation that represents the breakdown of sugar:

For this lab, you will compare experimental and theoretical results for how much carbon dioxide (CO2) is produced when sugar (C12H22O11) is broken down in water (H20), using yeast as a catalyst.

 

Materials:

  • 4 packets of quick rise yeast (we will use 2 packets but it is good to have extra on hand just in case)
  • a small soda or water bottle (500 mL)
  • 1/4 cup of white sugar (we will use 1 tsp = 5 mL, but it is good to have extra on hand just in case)
  • 3 balloons (we will use 1 balloon, but it is good to have extra on hand just in case)
  • 1 meter of string
  • 1 teaspoon measuring spoon
  • a balance for measuring mass (optional)
  • a meter stick

 

The rest of the instructions are in Sakai Resources > Classwork > Gases.

Oct 12

Potato Chip Road Trip

In class on Tuesday, you will watch this 97 second video:

After you are done, answer the following question:

Given what you know now, do your best to explain why the potato chip bag changed as the girl went from high altitude to low altitude.  Tweet your answer using #potatochipgas.