AP+Chem+Thermodynamics

Will a chemical reaction happen without the constant addition of energy? Will a chemical reaction release energy? These questions can be answered using the ideas of thermodynamics.

The first assignment in this unit is a review of calorimetry, found in the worksheets on the right. The chemical energy measured in calorimetry is called enthalpy, H. || Chapter 11 of the Addison-Wesley text will explain all of the ideas in the worksheet packet.
 * Date the work is assigned || Date the work is due || Summary of Idea || Readings (from Brown-LeMay unless specified otherwise) || Worksheets and assignments ||
 * ||  || A simple styrofoam cup is our key to unlocking nature's profound secrets regarding energy.

In Brown-LeMay, you can read Sections 5.4 and 5.5 for a more in-depth explanation of the same ideas related to calorimetry.

The first three sections of Chapter 5 present a detailed explanation of energy changes. They are good to read, but not essential in the beginning. ||  || It is introduced and reviewed on the following worksheets. || Section 5.6 ||  || 5.73 5.75 || Each of the above steps requires you to record a number in a data table: volume of liquid, initial temperature, mass of solid, and final temperature.
 * ||  || Hess Law states that the enthalpy changes for a series of reactions are additive.
 * March 7, 2012 || March 9, 2012 || The enthalpy of formation for a compound is determined experimentally. Using the information in Appendix C, we can predict whether a reaction is endothermic or exothermic || Section 5.7 || 5.71
 * March 9, 2012 || March 13, 2012 || Breaking bonds requires energy. Making bonds releases energy. The energy needed to make or break a bond is known as the bond enthalpy. The bond enthalpies on page 301 and the formula on page 302 can be used to calculate the enthalpy of reaction. || Section 8.8 (page 300) || 8.61, 8.63, 8.65, 8.67, 8.84 ||
 * March 9 || March 13 || Prepare a procedure and data table for lab on Tuesday. The purpose of the lab is to test the assumption's of Hess' Law. || The procedure for using a calorimeter is
 * 1) Add a known amount of liquid to the calorimeter.
 * 2) Measure the initial temperature of the liquid.
 * 3) Add a known amount of solid to the calorimeter.
 * 4) Measure the final temperature of the mixture once the reaction has stopped.

Listed below are the trials you will perform. Each listing has this format: (volume of liquid in the calorimeter) / (solid being added). The final mixture involves two liquids instead of a solid being added to a liquid. ||  || 19.31 19.37 19.43 19.45 19.49 ||
 * 100 mL HCl / piece of magnesium
 * 100 mL HCl / small amoung of MgO
 * 100 mL HCl / piece of NaOH
 * 100 mL H2O / piece of NaOH
 * 50 mL HCl / 50 mL NaOH solution*
 * March 15 || March 19 || A spontaneous reaction is one that releases free energy. By considering the enthalpy and entropy changes for a reaction, we can predict spontaneity. || The first two sections of Chapter 19 present a detailed explanation of spontaneity. They are good to read, but not essential in the beginning. Sections 19.3-6 are the core material, and I suggest you look at these core summaries:
 * the list at the top of page 752
 * equation [19.8] on page 753
 * equation [19.11] on page 755
 * equation [19.13] on page 757
 * table 19.3 on page 757
 * table 19.4 on page 760 || 19.1

Here is a page of experimental results from 2010-2011.

Answers to Multiple Choice review questions given in class, March 23, 2012 1. C 2. C 3. D 4. D 5. D 6.A 7. B 8. B