ACS study guide
ACS · Work through your exam, one topic at a time.
The ACS Certified Chemist credential is a professional certification offered by the American Chemical Society for chemists who want independent, third-party validation of their breadth of knowledge across the chemical sciences. It appeals to recent graduates entering industry, experienced bench chemists seeking formal recognition, and professionals moving into roles where demonstrated competence across subdisciplines matters, such as quality, regulatory, or research leadership. The ACS study guide has 6 sections and about 2,502 words.
01Analytical Chemistry
Analytical Chemistry on the ACS exam rewards quantitative reasoning: how a measurement is calibrated, how uncertainty and detection limits are reported, how mixtures are separated, and how spectroscopic and electrochemical signals become concentrations. Expect calculation-heavy items rather than descriptive recall.
479 words, about 2 min02Organic Chemistry
Organic Chemistry items on the ACS exam are mechanism- and structure-driven: assigning stereochemistry, predicting substitution and elimination outcomes, ranking acidity and carbonyl reactivity, and extracting structure from IR, NMR, and mass spectra. CIP priorities follow atomic number; a doubly bonded atom is treated as bonded to two copies of the same atom, so a carbonyl carbon counts as two oxygens.
453 words, about 2 min03Physical Chemistry
Physical Chemistry items test whether you can move between thermodynamic, kinetic, quantum, and electrochemical descriptions of one system without losing signs, units, or standard-state conventions. ΔG = ΔH − TΔS governs spontaneity at constant T and P; ΔG < 0 means spontaneous, and ΔG = 0 at equilibrium.
366 words, about 2 min04Inorganic Chemistry
Inorganic Chemistry items probe periodicity, bonding models (VSEPR, molecular orbital, crystal field), symmetry, coordination chemistry, and descriptive trends across the d and p blocks. Effective nuclear charge rises across a period, shrinking radii and raising ionization energy; radii grow down a group as n increases.
417 words, about 2 min05Biochemistry
Biochemistry items reward quantitative relationships: acid–base behavior of amino acids, enzyme kinetics and inhibition patterns, bioenergetics, and the logic of the central metabolic pathways. pI is the average of the two pKa values bracketing the neutral zwitterion: glycine (2.34, 9.60) gives pI 5.97; lysine uses its side-chain pKa near 10.5, giving pI near 9.7.
392 words, about 2 min06Polymer Chemistry
Polymer Chemistry items cover molar-mass averages and distributions, step- versus chain-growth kinetics, the Carothers equation, thermal transitions, and how chain structure controls solid-state properties. Number average Mn = ΣNiMi/ΣNi, weight average Mw = ΣNiMi²/ΣNiMi, and Mw ≥ Mn always, so PDI = Mw/Mn ≥ 1.
395 words, about 2 min