High School Chemistry  ·  Practice Hub

High School Chemistry Practice Problems

Stuck on a chemistry problem? Try it, check it, and read exactly how it’s solved. 2,642 practice problems with full worked solutions.

01 Pick a unit you are in right now and work on the topic that will help you most. Not sure? Start with the unit guide.
02 Try the samples first and notice what the problem is really asking you to do — not just whether you got it right.
03 Choose your problem type — calculation, concept, or multi-step — when you want to drill one kind of thinking specifically.
04 Generate a set — Quick (3), Standard (9), or Extended (18) — and use the worked solution to sharpen your thinking while the idea is still fresh.
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Start with the unit you need right now

Every unit has 3 free problems to start. Premium opens longer sets when you want more practice on the same skill.

Unit 1 215 problems
Quick 3 • Standard 9 • Extended 18
Intro to Chemistry & Lab Safety
Significant figures, unit conversions, and lab safety — the vocabulary-heavy start of chemistry.
Calculation Concept Multi-step
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Unit 2 179 problems
Quick 3 • Standard 9 • Extended 18
Matter
Physical vs. chemical changes, pure substances vs. mixtures. The vocabulary is usually harder than the ideas.
Calculation Concept Multi-step
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Unit 3 174 problems
Quick 3 • Standard 9 • Extended 18
Atomic Structure
Protons, neutrons, electrons, and isotopes. This unit is mostly about reading the notation correctly — and getting every number in the right place.
Calculation Concept Multi-step
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Unit 4 171 problems
Quick 3 • Standard 9 • Extended 18
Electron Configuration
Orbital filling rules and full electron configurations. You will usually lose points on the exceptions, not the basics.
Calculation Concept Multi-step
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Unit 5 174 problems
Quick 3 • Standard 9 • Extended 18
Periodic Table & Trends
Electronegativity, atomic radius, ionization energy. Expect comparison questions, not just definitions.
Calculation Concept Multi-step
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Unit 6 174 problems
Quick 3 • Standard 9 • Extended 18
Nomenclature
Naming ionic and covalent compounds. The rules are learnable — the problem is applying the right set to the right compound.
Concept Multi-step
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Unit 7 174 problems
Quick 3 • Standard 9 • Extended 18
Moles
Mole conversions — mass, particles, moles, molar mass. If you are still unclear on the factor-label method, this is the unit to nail down first.
Calculation Concept Multi-step
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Unit 8 174 problems
Quick 3 • Standard 9 • Extended 18
Chemical Reactions
Reaction types and balancing equations. You can probably balance an equation. Naming the reaction type is the harder part.
Calculation Concept Multi-step
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Unit 9 174 problems
Quick 3 • Standard 9 • Extended 18
Stoichiometry
Mole ratios, limiting reagents, and percent yield. This is where stoichiometry gets harder, so take the mole ratio one step at a time.
Calculation Concept Multi-step
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Unit 10 171 problems
Quick 3 • Standard 9 • Extended 18
Chemical Bonding
Lewis structures, bond types, and polarity. Drawing the structure correctly is half of every problem in this unit.
Calculation Concept Multi-step
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Unit 11 174 problems
Quick 3 • Standard 9 • Extended 18
Energy and Thermochemistry
Heat flow and calorimetry calculations. The equations are straightforward — the sign conventions are where you are most likely to slip.
Calculation Concept Multi-step
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Unit 12 174 problems
Quick 3 • Standard 9 • Extended 18
Gas Laws
Gas law relationships and the ideal gas equation. If the variables are not straight in your head, these problems fall apart fast.
Calculation Concept Multi-step
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Unit 13 172 problems
Quick 3 • Standard 9 • Extended 18
Solutions
Molarity, dilution, and solution calculations. There are more unit conversions here than you would expect.
Calculation Concept Multi-step
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Unit 14 171 problems
Quick 3 • Standard 9 • Extended 18
Chemical Equilibrium
Keq expressions, ICE tables, and Le Chatelier's Principle. Give this unit the time it needs — the ideas connect in ways that take a moment to land.
Calculation Concept Multi-step
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Unit 15 171 problems
Quick 3 • Standard 9 • Extended 18
Acids & Bases
pH calculations, strong vs. weak acids, and neutralization. The log math is only part of what makes this unit hard.
Calculation Concept Multi-step
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Looking for one skill instead of a whole unit? Each of these pages has 3 free interactive problems with worked solutions.

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High School Chemistry · Practice Hub