The Chemistry CLEP exam covers material that is usually taught in a one-year college course in general chemistry. Understanding of the structure and states of matter, reaction types, equations and stoichiometry, equilibrium, kinetics, thermodynamics, and descriptive and experimental chemistry is required, as is the ability to interpret and apply this material to new and unfamiliar problems. During this examination, an online scientific calculator function and a periodic table are available as part of the testing software.
The examination contains approximately 75 questions to be answered in 90 minutes.
A scientific (nongraphing) calculator is built into the exam software and is available to students during the entire testing time. Students are expected to know how and when it’s appropriate to use the calculator.
If you’re planning to take Chemistry prior to January 28, 2018, visit this site for a brief video tutorial and to download a free practice version for a 30-day trial period. Students are expected to download the calculator and become familiar with using it before taking the exam.
If you’re testing after January 28, 2018, it’s possible you’ll see a new version of the scientific calculator, the TI-30XS MultiView™. Information about the new version is available here. Practice with the calculators at both sites because you may get either version in your exam.
Students will find the online scientific calculator helpful in performing calculations (e.g., arithmetic, exponents, roots, logarithms).
Knowledge and Skills Required
Questions on the Chemistry examination require candidates to demonstrate one or more of the following abilities.
- Recall—remember specific facts; demonstrate straightforward knowledge of information and familiarity with terminology
- Application—understand concepts and reformulate information into other equivalent terms; apply knowledge to unfamiliar and/or practical situations; use mathematics to solve chemistry problems
- Interpretation—infer and deduce from data available and integrate information to form conclusions; recognize unstated assumptions
The subject matter of the Chemistry examination is drawn from the following topics. The percentages next to the main topics indicate the approximate percentage of exam questions on that topic.
Structure of Matter (20%)
Atomic theory and atomic structure
- Evidence for the atomic theory
- Atomic masses; determination by chemical and physical means
- Atomic number and mass number; isotopes and mass spectroscopy
- Electron energy levels: atomic spectra, quantum numbers, atomic orbitals
- Periodic relationships, including, for example, atomic radii, ionization energies, electron affinities, and oxidation states
- Binding forces
- Types: covalent, ionic, metallic, macromolecular (or network), dispersion, hydrogen bonding
- Relationships to structure and to properties
- Polarity of bonds, electronegativities
- Geometry of molecules, ions, and coordination complexes: structural isomerism, dipole moments of molecules, relation of properties to structure
- Molecular models
- Valence bond theory; hybridization of orbitals, resonance, sigma and pi bonds
- Other models, for example, molecular orbital
- Nuclear equations, half-lives, and radioactivity; chemical applications
States of Matter (19%)
- Laws of ideal gases; equations of state for an ideal gas
- Kinetic-molecular theory
- Interpretation of ideal gas laws on the basis of this theory
- The mole concept; Avogadro’s number
- Dependence of kinetic energy of molecules on temperature: Boltzmann distribution
- Deviations from ideal gas laws
Liquids and solids
- Liquids and solids from the kineticmolecular viewpoint
- Phase diagrams of one-component systems
- Changes of state, critical phenomena
- Types of solutions and factors affecting solubility
- Methods of expressing concentration
- Colligative properties; for example, Raoult’s law
- Effect of interionic attraction on colligative properties and solubility
Reaction Types (12%)
Formation and cleavage of covalent bonds
- Acid-base reactions; concepts of Arrhenius, Brønsted-Lowry, and Lewis; amphoterism
- Reactions involving coordination complexes
- Oxidation number
- The role of the electron in oxidation-reduction
- Electrochemistry; electrolytic cells, standard half-cell potentials, prediction of the direction of redox reactions, effect of concentration changes
Equations and Stoichiometry (10%)
- Ionic and molecular species present in chemical systems; net-ionic equations
- Stoichiometry: mass and volume relations with emphasis on the mole concept
- Balancing of equations, including those for redox reactions
Concept of dynamic equilibrium, physical and chemical; LeChâtelier’s principle; equilibrium constants
- Equilibrium constants for gaseous reactions in terms of both molar concentrations and partial pressure (Kc, Kp)
- Equilibrium constants for reactions in solutions
- Constants for acids and bases; pK; pH
- Solubility-product constants and their application to precipitation and the dissolution of slightly soluble compounds
- Constants for complex ions
- Common ion effect; buffers
- Concept of rate of reaction
- Order of reaction and rate constant: their determination from experimental data
- Effect of temperature change on rates
- Energy of activation; the role of catalysts
- The relationship between the rate-determining step and a mechanism
First law: heat of formation; heat of reaction; change in enthalpy, Hess’s law; heat capacity; heats of vaporization and fusion
Second law: free energy of formation; free energy of reaction; dependence of change in free energy on enthalpy and entropy changes
Relationship of change in free energy to equilibrium constants and electrode potentials
Descriptive Chemistry (14%)
The accumulation of certain specific facts of chemistry is essential to enable students to comprehend the development of principles and concepts, to demonstrate applications of principles, to relate fact to theory and properties to structure, and to develop an understanding of systematic nomenclature that facilitates communication. The following areas are normally included on the examination:
- Chemical reactivity and products of chemical reactions
- Relationships in the periodic table: horizontal, vertical, and diagonal
- Chemistry of the main groups and transition elements, including typical examples of each
- Organic chemistry, including such topics as functional groups and isomerism (may be treated as a separate unit or as exemplary material in other areas, such as bonding)
Experimental Chemistry (9%)
Some experiments are based on laboratory experiments widely performed in general chemistry and ask about the equipment used, observations made, calculations performed, and interpretation of the results. The questions are designed to provide a measure of understanding of the basic tools of chemistry and their applications to simple chemical systems.
User Test Results for the Chemistry CLEP Exam
342 users have submitted their test results to us since March 2016
320 (93.7%) of those users have reported an ACE recommended passing score
The table below represents our users most recent test results for the Chemistry CLEP exam after using Credits4Less.
Note: The date shown below represents the date that they reported their score to us.
|Feb 18, 2018||Pass||52|
|Feb 13, 2018||Pass||69|
|Feb 10, 2018||Pass||76|
|Jan 29, 2018||Pass||62|
|Jan 28, 2018||Pass||54|
Our Study Guide
Credits4Less’ Chemistry study guide will leave you fully prepared to pass your Chemistry CLEP exam. Our study guide is broken down to match the exact make up of the actual CLEP exam with each unit containing a set of cheat sheet notes and dozens of practice questions.