DOC PREVIEW
Seattle Central CHEM 161 - Exam 2 Study Guide - CHEM 161

This preview shows page 1 out of 3 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

CHEM 161 Exam 2 Study Guide F2014 page 1 of 3 CHEM 161: Exam 2 Study Guide Chapter 3: Stoichiometry Stoichiometry: Use mole‐to‐mole ratios to relate amounts of reactants and/or products Limiting Reagent Problems – Calculate the mass, volume, or concentration of product that can be made from each of given amount of reactants and using chemical equation. – Calculate the amount of reactant in excess that remains after the reaction. – Recognize that you need to calculate moles—not mass!—to determine the molarity of a product or reactant in excess. Yields of Reactions – theoretical yield: amount of product predicted using the balanced equation when limiting reagent is used up (can be calculated) – actual yield: amount of product one actually gets (generally given in the problem) Percent yield = – Given the percent yield for a reaction, determine the amount of reactant required for a given amount of product Chapter 4: Types of Chemical Reactions Aqueous Solutions: liquid or solid solute in H2O – solution: mixture of 2 or more substances – solute: substance present in smaller amount – solvent: substance present in larger amount Precipitation Reactions – precipitate (ppt): solid forming from 2 solutions – Use Solubility Rules to determine if ppt forms – Predict products of a reaction given reactants and Solubility Rules. – Predict all of the precipitates that would form when various ionic compounds are dissolved in the same beaker. Acid‐Base Neutralization Reactions – Know Arrhenius and Bronsted‐Lowry (B‐L) definitions for acids and bases – Identify B‐L acid/base in a chemical equation – Predict products for acid‐base reactions – HX + MOH  water + salt – HX + MHCO3  water + CO2 + salt – HX + MCO3  water + CO2 + salt Oxidation‐Reduction (Redox) Reac tions – Determine oxidation #’s for atoms in equations. – Use oxidation # to determine the reactant oxidized (reducing agent) and reactant reduced (oxidizing agent) – Determine the # of electrons gained or lost. Oxidation‐Reduction (Redox) Reac tions – Predict products given reactants for: – Combination reaction – metal + nonmetal  ionic compound (s) – Single‐replacement reactions – Activity Series, list of Active Metals, and Solubility Rules, where reactants are: – solid metal + metal solution – solid metal + acid – solid metal + H2O(l) – Combustion reaction – CxHy + O2  CO2 (g) + H2O (g) – CxHyOz + O2  CO2 (g) + H2O (g) – Balance and identify Decomposition reactions Strong, Weak and Non‐Electrolytes – strong electrolyte: breaks up completely  many ions present to conduct electricity – e.g. strong acids & bases, aqueous salts – weak electrolyte: breaks up to small degree  only few ions present to conduct electricity – e.g. weak acids & bases, insoluble salts – nonelectrolyte: a molecular compound that forms molecules in water  no ions  does not conduct electricity CHEM 161 Exam 2 Study Guide F2014 page 2 of 3 Chapter 4: Types of Chemical Reactions (Continued) Acids and Bases as electrolytes – Know strong acids and strong bases in notes! – All other acids and bases are weak – Know how H2SO4 dissociates in water. Chemical Equations and (Net) Ionic Equations – Chemical Equation: compounds shown as whole – Complete/Total Ionic Equation: – shows strong electrolytes as separated ions – Spectator Ions: unchanged in chemical reaction – Net Ionic Equation: Shows what substances change in a chemical reaction Guidelines for writing Net Ionic Equations: 1. Complete and balance molecular/chem equation 2. Leave solids, liquids, gases, weak electrolytes as compounds; break up strong electrolytes 3. Cancel spectator ions 4. Simplify coefficients if possible 5. If all reactants and products cancel (all spectator ions)  NR Experimental Observations of Double‐Replacement Precipitation and Acid‐Base Neutralization Reactions – Given a table of experimental results similar to the “Double Replacement/Metathesis” experiment, determine the cation and anion that must be present in a solution of an unknown soluble ionic compound Oxidation‐Reduction (Redox) Reac tions – Be able to determine oxidation numbers for all the atoms/elements in a chemical equation. – Use oxidation numbers to determine which reactant was oxidized (reducing agent) and which reactant was reduced (oxidizing agent) – Determine the # of electrons gained or lost. Balance redox reactions in acidic and basic solution using the half‐reaction method. – Balance atoms and electrons transferred, then balance O atoms using H2O and H atoms using H+ ions (in acidic solution) – In basic solution, neutralize H+ ions with OH‐ ions – Cancel H+, OH‐, and H2O on both sides of the equation and simplify coefficients Molarity, Solution Stoichiometry, and Volumetric Analysis Calculations – Use molarity and volume to solve for moles. – Use balanced chemical equation to determine mole‐to‐mole ratios needed to solve problems. – Calculate the molarity of a compound or an ion in a solution. – Use the dilution equation: M1 V1 = M2 V2 for dilution problems Acid‐Base Titrations – Know the definitions for standard solution, acid‐base indicators, titration, and endpoint. – Solve problems using titration data. Mass Percent Concentraton: M/M%=mass of solute×100%mass of solution – Solve for or use mass percent concentration in various calculations. – Solve for mass percent concentration for mixtures (e.g. % CaCO3 in limestone) – Solve a variety of problems combining molarity, mass percent concentration, and topics covered from previous chapters. Chapter 6: Properties of Gases - Know the physical properties of gases. - Know the elements and common compounds that exist as gases at 25˚C and 1 atm pressure. - Know the definitions for the following: vacuum, gas pressure, atmospheric pressure, barometer, and manometer - Know how a manometer works, and be able to solve for gas pressure. CHEM 161 Exam 2 Study Guide F2014 page 3 of 3 Chapter 6: Properties of Gases Gas pressure and Atmospheric pressure – Standard atmospheric pressure: 760 torr at 0˚C at sea level – Be able to convert between units of


View Full Document
Download Exam 2 Study Guide - CHEM 161
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Exam 2 Study Guide - CHEM 161 and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Exam 2 Study Guide - CHEM 161 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?