Chemistry Regents Reference Table & Formulas
The official Reference Tables for Physical Setting / Chemistry, plus key Chemistry formulas, concepts, and vocabulary to know for the exam.
The official Reference Tables for Physical Setting / Chemistry
Provided with every Chemistry Regents booklet. Current edition: 2025 edition (current).
What's inside the Reference Tables for Physical Setting / Chemistry:
- Periodic Table of the Elements (with electron configurations)
- Solubility Curves (table G) and Solubility Guidelines (table F)
- Selected Polyatomic Ions (table E)
- Activity Series of metals and nonmetals (table J)
- Selected Thermodynamic Properties, ΔHf, ΔGf, S° (table I)
- Heats of Reaction at 101.3 kPa (table I)
- Vapor Pressure of Four Liquids (table H)
- Important formulas, density, dilution, gas laws, heat, pH
Most Chemistry Regents questions are TABLE-LOOKUP questions in disguise. Open the PDF before you study a topic, half the time the answer's already on the sheet and you just need to find it fast.
Key Chemistry formulas
| Name | Formula | What it's for |
|---|---|---|
| Density | $D = \dfrac{m}{V}$ | Mass per unit volume. Standard units in chem: $g / cm^3$ for solids, $g / mL$ for liquids. (On the official sheet.) |
| Moles from mass | $n = \dfrac{m}{M}$ | $n$ moles, $m$ grams, $M$ molar mass (g/mol). The bridge between lab and stoichiometry. |
| Molarity | $M = \dfrac{\text{mol solute}}{\text{L solution}}$ | How concentrated a solution is. $M$ means mol per liter. (On the official sheet.) |
| pH | $\mathrm{pH} = -\log[\mathrm{H}^+]$ | Lower pH → more acidic. pH 7 is neutral. Each unit is a factor of 10 in $[\mathrm{H}^+]$. |
| pOH and the pH/pOH sum | $\mathrm{pH} + \mathrm{pOH} = 14$ | At 25°C. If you know one, you know the other. |
| Combined gas law | $\dfrac{P_1 V_1}{T_1} = \dfrac{P_2 V_2}{T_2}$ | Same gas, two conditions. T must be in Kelvin. (On the official sheet.) |
| Ideal gas law | $PV = nRT$ | Connects pressure, volume, moles, and temperature. $R = 0.0821$ L·atm/(mol·K). |
| Heat absorbed / released | $q = mc\Delta T$ | $m$ in g, $c$ specific heat (J/g·°C), $\Delta T$ change in temperature. (On the official sheet, c-values too.) |
| Percent yield | $\%\text{ yield} = \dfrac{\text{actual}}{\text{theoretical}} \times 100$ | How much product you actually got versus the stoichiometry prediction. (On the official sheet.) |
| Avogadro's number | $N_A = 6.022 \times 10^{23}$ | Particles per mole. Goes between mole count and number of atoms or molecules. |
Key concepts
- Periodic trends — Atomic radius: down ↑, across →. Ionization energy and electronegativity: opposite. Memorize the direction, derive the rest.
- Bonding: ionic vs covalent — Big EN gap → ionic (metal + nonmetal). Small gap → covalent (two nonmetals). Polar covalent sits in between.
- Acids and bases (Arrhenius) — Acid: donates $\mathrm{H}^+$ in water. Base: donates $\mathrm{OH}^-$. Strong acids fully ionize; weak ones don't.
- Titration — Neutralize an unknown acid (or base) with a known volume of base (or acid). At the equivalence point, $M_a V_a = M_b V_b$ (1:1 reactions).
- Endothermic vs exothermic — Endo: absorbs heat ($\Delta H > 0$); products are higher in energy. Exo: releases heat ($\Delta H < 0$); products are lower.
- Catalyst — Speeds a reaction by lowering activation energy, but is not consumed. Doesn't change $\Delta H$ or the equilibrium position.
- Le Châtelier's principle — A system at equilibrium shifts to oppose a change. Add reactant → shifts right. Add product → shifts left.
- States of matter — Solid: fixed shape and volume. Liquid: fixed volume, takes shape. Gas: fills its container. Plasma exists but is off the Regents.
Must-know vocabulary
- Atom — Smallest unit of an element. Protons (+) and neutrons (0) in the nucleus; electrons (−) around it.
- Element — A pure substance defined by its proton count (atomic number).
- Isotope — Atoms of the same element with different neutron counts → different mass numbers.
- Ion — An atom (or group) with a charge. Cation: positive (lost electrons). Anion: negative (gained electrons).
- Compound — Two or more elements chemically bonded in a fixed ratio.
- Mole — Avogadro's number of particles. Used to bridge atomic-scale and gram-scale.
- Molarity (M) — Moles of solute per liter of solution. The standard concentration unit.
- Catalyst — Speeds a reaction without being consumed by it.
- Electronegativity — How strongly an atom pulls bonding electrons toward itself. Fluorine is the highest.
- STP — Standard temperature and pressure: 273 K and 1 atm. One mole of any ideal gas occupies 22.4 L at STP.
- Equilibrium — Forward and reverse rates are equal. Concentrations stop changing, though both reactions are still running.
Frequently asked questions
Do you get a reference table on the Chemistry Regents?
Yes. The official Reference Tables for Physical Setting / Chemistry is provided with every Chemistry Regents booklet, so practice with it open.
What formulas do you need for the Chemistry Regents?
The most-used Chemistry formulas are on this page with what each one is for. There are 10 key formulas to know.