Chemistry Spring Semester Chemistry Unit 5 Test Study Guide Instructions: ** This study guide is intended to HELP you to study for the unit test, but it is not comprehensive. You should have read each lesson, completed the practice problems and quizzes and attended the class connect sessions before taking the test. Additional resources: http://www.sparknotes.com/testprep/books/sat2/chemistry/chapter9.rhtml An online SAT review on equilibrium equations. http://misterguch.brinkster.net/gaslawworksheets.html (Worksheets with answer keys- Choose the rate expression worksheets, Le Chatelier’s Principle Worksheets, or collision theory worksheets). _____________________________________________________________________________ Come to a help session BEFORE the test if you can’t answer any of the questions below! Review: 1. Review from Unit 4: In an endothermic reaction, what has more energy, the reactants or the products? 2. Review from Unit 4: In an exothermic reaction, what has more energy, the reactants or the products? Lesson 1: Reaction Rates 1. Define: Reactants 2. Define: Products 3. What do the reactants have to do in order to react with each other? 4. Define: Activated complex (or Transition state) 5. Define: Activation Energy 6. What information is provided by an energy diagram. 7. Be able to describe what is happening in an energy diagram. 8. Be able to determine if an energy diagram represents an endothermic or exothermic reaction. 9. Draw a graph to represent the concentration of a reactant in a chemical reaction over time. 10. Draw a graph to represent the concentration of a product in a chemical reaction over time. Chemistry Spring Semester Chemistry Unit 5 Test Study Guide 11. Define: Catalyst 12. What does “consumed” mean in relation to a chemical reaction (this isn’t specifically in the lesson. Think about it and ask for help if you need help!) Lesson 2: Factors affecting reaction rates 1. List the factors that affect the rate of chemical reactions. 2. Describe how each factor affects the rate of a chemical reaction. 3. Describe what happens to an energy diagram with the addition of a catalyst 4. Define: Inhibitor 5. How does the orientation of the reactants affect a chemical reaction? 6. How is the rate of a reaction affected by addition of more reactants? 7. Provide some examples of biological catalysts. (You might want to do a bit of research, or recall from Biology). 8. What does the slope of a line tangent to the reaction curve represent? (This is NOT explained in the lesson, look at the curve and recall from algebra…what does the slope of ANY line tangent to a curve tell you?) 9. How would adding water to a reaction affect the reaction rate? 10. How might the temperature of the water make a difference? Lesson 3: Reaction Rate Lab (Complete Lesson 6 before doing this lab!) 1. What is the goal of this lab? Lesson 6: Collision Theory (Complete this lesson before the lab) 1. Define: Collision Theory 2. How can each factor that affects reaction rates (from lesson 2) be related to the collision theory? Lesson 9: Equilibrium 1. Define: reversible reaction 2. Define: chemical equilibrium 3. Define: Equilibrium Constant Chemistry Spring Semester Chemistry Unit 5 Test Study Guide 4. What factors affect the equilibrium of a chemical system? Lesson 10: Le Chatelier’s Principal 1. What equation is used to describe reaction rates? 2. What does an equilibrium expression (equation) tell you about a reaction? 3. Write the equation for the equilibrium constant for the following reaction: 8 Fe + S8 8 FeS 4. Given the equilibrium expression: Keq= [NH3]2 / [N2] [H2]3 What is the reaction? 5. If more reactant is added to a chemical reaction at equilibrium, what will happen? 6. If more product is added to a chemical reaction at equilibrium, what will happen? Lesson 11: Spontaneous Reactions 1. Define: Spontaneous Reaction 2. Define: Free Energy 3. What equation is used to represent free energy? 4. What does Gibbs free energy tell you about a chemical system? 5. Define: Gibbs Free Energy 6. Be able to calculate free energy 7. Define: Enthalpy Lesson 12: Entropy and Free Energy 1. Define: Entropy 2. What does entropy describe about a chemical system? 3. What is the equation used to solve for entropy? 4. Complete the following table by indicating which reaction types are usually spontaneous and which are usually non-spontaneous (the first set has been done for you): Spontaneous +H -H ----- +S -S +G -G Chemistry Spring Semester NonSpontaneous Chemistry Unit 5 Test Study Guide ------ 3. Which of the above indicators (H, S or G) is the most accurate for determining if a reaction is spontaneous? 4. What factors increase entropy and what factors decrease it?