Just a couple more weeks and summer break will be here. That means most high school students are preparing for finals right now. You can use this detailed study guide to prepare for finals for second-semester high school chemistry (regular and Honors). This guide covers how to study, what to study, and explanations for common points of confusion.
Especially for a subject like chemistry where there is a lot of math involved, doing practice problems are very important while preparing for an exam
Like in most other science courses, chemistry has some overarching themes and theories that are the foundations for more detailed topics. One great example is electronegativity. Make sure you understand these big concepts first
Well-labeled diagrams can really help clarify concepts. You can find these easily on Google Images. Then, try drawing the diagram out on your own to make sure you remember it
As you begin preparing for the final, first focus on reviewing concepts that are still confusing to you, or ones that you may have completely forgotten about. Those are your top priority. After that, review the following big foundational concepts:
What a chemical equation really represents/means
Be very familiar with the general layout of the periodic table, as well as the properties of each group (alkali metals, alkaline earth, gases, transition metals, halogens, and noble gases)
With a solid understanding of the foundational concepts, you can use them to correctly answer questions that you might not know the answer to right away.
Specific Topics Covered
The specific topics covered on the second-semester final may vary from school to school. Check with your class syllabus or final outline from your teacher on what topics and chapters are included on the exam. Here is a list of topics that are usually tested from second semester:
Behavior and properties of gases, the gas laws, law of diffusion, partial pressure
Physical phase changes, and the properties of each physical phase (gas, liquid, solid)
Thermodynamics -- energetics of a reaction, enthalpy and entropy, Hess’s Law, Gibbs free energy equation, specific heat calculations
Chemical equilibrium, Le Chatelier’s Principle, equilibrium constant calculations
Electrochemistry -- galvanic cells, redox (reduction-oxidation) reactions, using reduction potential charts to compare elements
Nuclear chemistry -- why nuclear radiation occurs, different types of nuclear radiation, predicting the identity of the daughter (resulting) cell after radiation
Answers to Common Questions
Diving deeper into these topics, the following are explanations for some common areas of confusion:
Physical states: Students tend to forget about sublimation and deposition. Although they are rare processes, they are still fair game for the exam. Sublimation is the transition of a solid directly into a gas. Deposition is the transition of a gas directly into a solid. Students often ask for some examples of these, since they are hard to imagine. An example of deposition in nature is frost (solid) forming on grass directly from water vapor (gas) in the air. An example of sublimation is when dry ice (solid) evaporates into gaseous CO2.
Thermodynamics: When calculating the equilibrium constant, never include liquids or solids in the equation. We exclude them because they will not affect the equilibrium state
Thermodynamics: Students are often confused about what enthalpy and entropy are. Enthalpy is the total heat present within a system. Of course, heat (thermal energy) will often flow in and out of an open system, so we often deal with the change in enthalpy in chemistry. Entropy is the amount of disorder in a system. A great example is ice versus water vapor. Both consist of water molecules, but the arrangements of those molecules are very different. The entropy of water vapor is much higher because they are more spread out, move around more randomly, and have more disorder overall. In contrast, the water molecules in ice are locked in formation.
Thermodynamics: specific heat problems seem simple enough based on the equation, but the difference between phase changes and temperature changes can get very confusing.
Redox terms: Reduction is gaining electrons, oxidation is losing electrons (OIL RIG). A reducing agent loses electrons and allows another element to be reduced. An oxidizing agent gains electrons and allows another element to be oxidized.
Reduction potentials: First, identify whether you are looking at a reduction or oxidation potential chart. The explanation here applies to reduction potentials. The lower you go on the chart, the more likely the elements are to be reduced (accept electrons), since they are more electronegative.
The final week before the exam should be reserved for doing practice problems and reviewing those nitty-gritty vocabulary terms that seem to keep escaping your memory. Especially for multiple-choice exams, it will really help to know all the important vocabulary terms. As for formulas and constants though, usually they are provided on a formula sheet for finals.
Hope this guide gave you an idea of how to prepare for your chemistry finals! Please leave a comment below if you have a specific question about a concept or practice problem.