Exam 1 Overview

This study guide summarizes the key concepts and skills required for Exam 1, covering Chapters 1–4 of a General Chemistry I course. Students should be able to apply, explain, and solve problems related to the following topics.

Chapter 1: Matter, Measurement, and Problem Solving

Classification and Properties of Matter

• Matter is anything that has mass and occupies space. It can be classified by state (solid, liquid, gas) and composition (element, compound, mixture).

• Physical properties are characteristics that can be observed without changing the substance's identity (e.g., melting point, density).

• Chemical properties describe a substance's ability to undergo chemical changes (e.g., flammability, reactivity).

Separation Techniques

• Filtration separates solids from liquids using a porous barrier.

• Distillation separates substances based on differences in boiling points.

Measurement and Units

• Use the SI system for standard units: meter (length), kilogram (mass), second (time), mole (amount), etc.

• Understand prefix multipliers (e.g., kilo-, milli-, micro-) and derived units (e.g., density: kg/m3).

• Be able to convert between units and use conversion factors.

Precision and Accuracy

• Precision refers to the consistency of repeated measurements.

• Accuracy refers to how close a measurement is to the true value.

• Understand the difference and be able to calculate percent error.

Significant Figures

• Apply rules for determining the number of significant figures in measurements and calculations.

• Use significant figures in calculations involving addition, subtraction, multiplication, and division.

Dimensional Analysis

• Use dimensional analysis (factor-label method) to solve problems involving unit conversions.

• Example: Convert 25.0 cm to meters using

Chapter 2: Atoms and Elements

Atomic Theory and Structure

• Understand the Law of Conservation of Mass: Mass is neither created nor destroyed in chemical reactions.

• Know the Law of Definite Proportions: A compound always contains the same proportion of elements by mass.

• Know the Law of Multiple Proportions: When two elements form more than one compound, the ratios of the masses of the second element that combine with a fixed mass of the first element are simple whole numbers.

• Be familiar with the experiments of Thomson (discovery of the electron), Millikan (oil drop experiment, electron charge), and Rutherford (gold foil experiment, nuclear model).

Atomic Structure

• Know the basic structure of the atom: protons, neutrons, electrons.

• Understand isotopes: Atoms of the same element with different numbers of neutrons.

• Calculate average atomic mass using isotopic abundances:

Periodic Table and Element Classification

• Know how elements are arranged in the periodic table by atomic number.

• Classify elements as metals, nonmetals, or metalloids.

• Predict the charge of ions based on group position.

Mass Spectrometry

• Understand the use of mass spectrometry in determining isotopic composition and atomic mass.

Chapter 3: Molecules and Compounds

Types of Chemical Bonds and Formulas

• Identify types of bonds: ionic (transfer of electrons), covalent (sharing of electrons).

• Distinguish between empirical, molecular, and structural formulas.

• Write and interpret chemical formulas.

Elements, Compounds, and Naming

• Know the difference between an atom and a molecule.

• Classify substances as elements or compounds.

• Memorize common cations and anions and their names.

• Apply rules for naming ionic and molecular compounds.

• Be able to write names from formulas and vice versa.

Calculations Involving Compounds

• Calculate the number of molecules, formula units, ions, or atoms using Avogadro's number ().

• Calculate mass of a substance from chemical formula.

• Determine empirical and molecular formulas from experimental data.

• Apply conversion factors between mass and chemical formula.

Organic and Inorganic Compounds

• Distinguish between organic (carbon-containing) and inorganic compounds.

• Identify and name functional groups.

• Write names and formulas for simple straight-chain hydrocarbons.

Chapter 4: Chemical Reactions and Stoichiometry

Types of Chemical Reactions

• Identify and classify chemical reactions: synthesis, decomposition, single replacement, double replacement, combustion.

• Write balanced chemical equations for reactions.

Stoichiometry

• Perform stoichiometric calculations using balanced equations.

• Determine limiting reactant and calculate amounts in excess.

• Calculate theoretical yield and percent yield:

Combustion and Special Reactions

• Understand the importance of combustion reactions.

• Predict products and write balanced equations for combustion reactions.

• Write balanced equations for reactions of alkali metals and halogens.

Key Tables

Common Prefix Multipliers (SI Units)

Classification of Matter

Types of Chemical Formulas

Additional info:

• Some content was inferred and expanded for completeness, such as definitions, examples, and formulas.

• Tables were constructed to summarize key comparisons and classifications.