Exam #3 Study Guide (Chapters 7, 8, 9) PDF

Exam #3 (Chapters 7,8,9) Study Guide Chapter 7: Chemical Reactions and Chemical Quantities Equations and constants (will be provided on the exam) % Yield = actual yield/theoretical yield x 100% Concepts/Skills to Know Be able to write a balanced...

Exam #3 (Chapters 7,8,9) Study Guide Chapter 7: Chemical Reactions and Chemical Quantities Equations and constants (will be provided on the exam) % Yield = actual yield/theoretical yield x 100% Concepts/Skills to Know Be able to write a balanced equation for a chemical reaction based on chemical names, formulas or type of reaction (i.e. combustion). Stoichiometry – know how to use coefficients of balanced chemical equations as conversion factors. (The mole tunnel…) Know how to identify the limiting reactant and excess reactant and to calculate theoretical yield, percent yield, and amount of excess reactant in a reaction. Types of reactions – be able to predict the products and balance chemical reactions for combustion reactions and alkali metal reactions. Chapter 8: Introduction to Solutions and Aqueous Reactions Equations and Constants (will be provided on exam) MV = MV 1 1 2 2 Concepts/Skills to Know Be familiar with the components of a solution (solute and solvent) Solution concentration – Be familiar with the concentration unit of molarity (M) and how to use it as a conversion factor in solution stoichiometry. Know how to prepare a dilute solution and be able to perform dilution calculations using MV = MV 1 1 2 2 Types of aqueous solutions – know the difference between electrolytes and non- electrolytes, and the process of how each dissolves in water. Solubility – MEMORIZE the solubility rules and be able to predict whether a product of a precipitation reaction would be soluble or insoluble. Be able to write the molecular, complete ionic, and net ionic equations for a reaction between two aqueous solutions. Acids and bases: o Know the definitions of Arrhenius acids and bases o Be able to name acids (both binary and oxyacids) o Be able to predict the products and write the balanced chemical equations for acid/base reactions Oxidation-reduction (redox) reactions: o Know the definitions of oxidation and reduction o Be able to assign oxidation states to individual elements in a reaction (MEMORIZE the rules in the correct order) o Be able to identify whether or not a reaction is a redox reaction o Be able to identify what has been oxidized and reduced in a redox reaction. o Be able to identify the reducing agent and oxidizing agent in a redox reaction  Chapter 9:Thermochemistry Equations and Constants (will be provided on exam) q = mCsT q = –q sys surr Concepts/Skills to Know Energy – Be familiar with the two main types of energy (Kinetic, Potential), as well as the examples of each we focused on in class (Thermal and Chemical) and how they interconvert. Know the differences between energy, heat, enthalpy, and temperature as well as how they relate to one another. Know the units associated with each. Know what the + or – signs on E, H tell us about whether a reaction is endothermic or exothermic. Be familiar with the first law of thermodynamics and how it relates to energy interactions between a system and its surroundings. Know what specific heat capacity tells us about a substance and be able to use specific heat capacity in calculations (q = mCsT). Know what happens at thermal equilibrium and be able to perform calculations describing substances at thermal equilibrium Be able to use a given ΔHrxn to perform stoichiometric conversions. (The mole tunnel!) Be able to solve problems involving the ΔHrxn using the following relationships: o Determining ΔHrxn by using Hess’s Law and manipulating equations and ΔH values. o Determining ΔHrxn from bond energies o Determining ΔHrxn from standard enthalpies of formation (ΔHof)