Chemistry Test Cheat Sheet 2026

The 30 highest-yield Chemistry Test facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Burning 1 mol of methane (CH₄) releases 890 kJ. How much heat is released burning 8 g of CH₄? (Molar mass CH₄ = 16 g/mol) → 445 kJ
2. Which indicator would be most appropriate for titrating a strong acid with a strong base? → Either methyl orange or phenolphthalein
3. What is the term for the minimum energy required to start a chemical reaction? → Activation energy
4. How many orbitals are present in the 4f subshell? → 7
5. What is the conjugate base of H₂SO₄? → HSO₄⁻
6. What is the primary advantage of inductively coupled plasma mass spectrometry (ICP-MS) over flame AAS? → Ability to measure multiple elements simultaneously at trace levels (ppt)
7. Which titration technique uses electrical conductance of the solution to determine the endpoint? → Conductometric titration
8. Which compound is known as quicklime? → Calcium oxide
9. Which intermolecular force is responsible for the unusually high boiling point of water? → Hydrogen bonding
10. What does a positive standard cell potential (E°cell > 0) indicate? → Spontaneous reaction
11. Which of the following electron configurations represents a violation of the Pauli Exclusion Principle? → 1s²1s² (two electrons with the same four quantum numbers)
12. A compound contains 40% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula? (C=12, H=1, O=16) → CH₂O
13. Which law states that the total energy of an isolated system is constant? → The First Law of Thermodynamics
14. Which spectroscopic technique is most useful for distinguishing between cis and trans isomers of alkenes based on coupling constants? → ¹H NMR spectroscopy
15. The boiling point elevation constant (Kb) for water is 0.512 °C/m. What is the boiling point of a 1.5 m KCl solution (assume i = 2)? → 101.536 °C
16. Which gas is evolved when zinc reacts with dilute hydrochloric acid? → Hydrogen
17. In ionic compounds, what determines the ratio of cations to anions? → The need for the compound to be electrically neutral
18. If equal volumes of 0.1 M HCl and 0.1 M NaOH are mixed, the resulting solution is: → Neutral with pH = 7
19. In electrochemistry, the standard cell potential E°cell is related to the standard Gibbs free energy by: → ΔG° = −nFE°cell
20. What is the relationship between theory and practice in Atomic Structure? → Theory provides the foundation; practice applies it to real situations
21. Which unit must temperature be expressed in when using the gas laws? → Kelvin
22. What is the mole fraction of ethanol (C₂H₅OH) in a solution containing 46 g of ethanol (MW=46 g/mol) and 180 g of water (MW=18 g/mol)? → 0.10
23. The solubility product constant (Ksp) for a sparingly soluble salt represents: → The equilibrium constant for the dissolution of a slightly soluble ionic compound
24. Which type of crystal structure does NaCl adopt? → Rock salt
25. Which of the following correctly describes a state function in thermodynamics? → Its value depends only on the current state of the system
26. What is the term for the measure of disorder in a system? → Entropy
27. How does documentation support quality in Chemical Bonding? → It creates records, ensures consistency, and enables improvement
28. A hydrate has the formula CuSO₄·xH₂O. A 25.0 g sample loses 7.2 g of water when heated. What is x? (CuSO₄=160, H₂O=18) → 5
29. Which expression correctly represents the equilibrium constant Kc for the reaction: N₂(g) + 3H₂(g) ⇌ 2NH₃(g)? → Kc = [NH₃]² / ([N₂][H₂]³)
30. What is the term for a reaction where two compounds exchange ions to form two new compounds? → Double displacement (metathesis)