Exam 3 Learning Goals (1)

CHM1045 Fall 2024 Exam 3 Study Guide

The exam will cover material presented in Lectures 15 through 20, including details discussed during recitation and workshops.

Definition of Solution: A solution is a homogeneous mixture consisting of two or more substances that are evenly distributed.
Components of Solution: Identify the different components, classifying them as solute (the substance being dissolved) or solvent (the substance doing the dissolving).
Aqueous Solutions: Solutions where water is the solvent are referred to as aqueous solutions.
Solubility Prediction: The solubility of substances can be predicted based on the dipole moments, which indicate how polar a compound is.
Ionic Compounds: Soluble ionic compounds dissociate into their respective ions when dissolved in a solvent, exhibiting characteristics of electrolytic solutions.
Electrolytic vs Nonelectrolytic Solutions: Understand the differences, where electrolytic solutions conduct electricity due to free ions, while nonelectrolytic solutions do not.

Units of Concentration: Understand various units of concentration, including percent by mass (wt%), percent by volume (vol%), parts per million (ppm), parts per billion (ppb), mole fraction, molarity, and molality.
Density Conversions: Master conversions necessary to switch between these units effectively.
Recognize the advantages of different concentration units in practical applications for real-world problem-solving.
Conversions: Be able to convert between molarity, amount of solute in moles, solute mass, and total solution volume.
Dilution Calculations: Calculate concentrations of diluted solutions that are derived from stock solutions using the dilution equation (C1V1 = C2V2).

Chemical Notation: Understand how to write chemical equations symbolizing the transformation from reactants to products.
Reaction Procedure: Be able to interpret procedural details indicated above or below the reaction arrow, including mixing, heating, or timing instructions.
Balancing Reactions: Learn the importance of balancing chemical equations to reflect the law of conservation of mass.
Stoichiometric Coefficients: Comprehend the significance of stoichiometric coefficients and how to use molar ratios to relate reactants and products quantitatively.

Limiting and Excess Reactants: Familiarize yourself with the concepts surrounding limiting and excess reactants, which determine the maximum amount of product formed.
Theoretical Product Yield: Predict the theoretical yield based on the limiting reactant present in the reaction.
Percent Yield Calculation: Learn how to calculate the percent yield of a reaction by comparing actual product yield to theoretical yield.
Titration Techniques: Understand the fundamentals of titration as a method to determine the concentrations of unknown reactants in solutions.

Ion Exchange Reactions: Practice predicting products in various types of reactions, including Bronsted-Lowry acid/base reactions and precipitation reactions.
Solubility Rules: Review the general solubility rules for ionic compounds, including:
- Generally Soluble: Group I metals, ammonium, nitrates, and acetates.
- Generally Soluble: Halides and sulfates unless they are combined with Ag+, Hg22+, or Pb2+.
- Generally Insoluble: Carbonates, phosphates, and hydroxides unless paired with Group I metals or ammonium.
Bronsted-Lowry Acids and Bases: Identify strong acids (e.g., HCl, HBr, HI, HNO3, HClO4, H2SO4) and weak acids (notably, carboxylic acid functional group -COOH).
Strong Bases: Recognize that soluble -OH salts (such as NaOH) function as strong bases.
Weak Base: Ammonia (NH3) is classified as a weak base.
Acid/Base Reactions: Be prepared to predict the products of acid/base reactions involving the acids and bases discussed.