General Chemistry Reference Sheet: Constants, Equations, and the Periodic Table

Reference Information for General Chemistry

Abbreviations and Symbols

This section provides a list of common abbreviations and symbols used in general chemistry, essential for interpreting equations and scientific notation.

• Δ: Change in (e.g., ΔE = change in energy)

• c: Speed of light

• h: Planck's constant

• R: Gas constant

• λ: Wavelength

• ν: Frequency

• n: Principal quantum number or amount (mol)

• M: Molarity (mol/L)

• P: Pressure

• V: Volume

• T: Temperature (K)

• q: Heat

• w: Work

• ΔH: Enthalpy change

• ΔS: Entropy change

• ΔG: Gibbs free energy change

Physical Constants

These constants are fundamental to solving problems in chemistry and physics.

• Speed of light (c): $c = 2.998 \times 10^8 \ \text{m/s}$

• Planck's constant (h): $h = 6.626 \times 10^{-34} \ \text{J} \cdot \text{s}$

• Gas constant (R): $R = 0.0821 \ \text{L} \cdot \text{atm} / \text{mol} \cdot \text{K}$ or $8.314 \ \text{J} / \text{mol} \cdot \text{K}$

• Avogadro's number (N_A): $N_A = 6.022 \times 10^{23} \ \text{mol}^{-1}$

• Faraday's constant (F): $F = 96,485 \ \text{C} / \text{mol}$

• Standard atmospheric pressure: $1 \ \text{atm} = 760 \ \text{mm Hg} = 101.325 \ \text{kPa}$

Key Equations

These equations are central to solving problems in general chemistry, including stoichiometry, gas laws, thermochemistry, and quantum mechanics.

• Ideal Gas Law: $PV = nRT$

• Combined Gas Law: $\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}$

• Density of a gas: $d = \frac{PM}{RT}$

• Dalton's Law of Partial Pressures: $P_{\text{total}} = \sum P_i$

• Boyle's Law: $P_1 V_1 = P_2 V_2$

• Charles's Law: $\frac{V_1}{T_1} = \frac{V_2}{T_2}$

• Avogadro's Law: $\frac{V_1}{n_1} = \frac{V_2}{n_2}$

• Energy of a photon: $E = h\nu = \frac{hc}{\lambda}$

• First Law of Thermodynamics: $\Delta E = q + w$

• Enthalpy change: $\Delta H = \Delta E + P\Delta V$

• Gibbs Free Energy: $\Delta G = \Delta H - T\Delta S$

• Beer-Lambert Law: $A = \varepsilon b c$

• Arrhenius Equation: $k = A e^{-E_a/RT}$

Periodic Table of the Elements

The periodic table organizes all known chemical elements by increasing atomic number, electron configuration, and recurring chemical properties. Elements are arranged in rows (periods) and columns (groups or families). Key features include:

• Groups: Vertical columns; elements in the same group have similar chemical properties.

• Periods: Horizontal rows; properties change progressively across a period.

• Metals, Nonmetals, Metalloids: The table is divided into these broad categories based on physical and chemical properties.

• Transition Metals: Elements in groups 3-12.

• Representative Elements: Groups 1, 2, and 13-18.

Common Unit Conversions and Relationships

• Temperature: $K = ^\circ C + 273$

• Pressure: $1 \ \text{atm} = 760 \ \text{mm Hg} = 101.325 \ \text{kPa}$

• Volume: $1 \ \text{L} = 1000 \ \text{mL}$

• Energy: $1 \ \text{cal} = 4.184 \ \text{J}$

Sample Table: Gas Law Relationships

Law	Equation	Variables Held Constant
Boyle's Law	$P_1 V_1 = P_2 V_2$	n, T
Charles's Law	$\frac{V_1}{T_1} = \frac{V_2}{T_2}$	n, P
Avogadro's Law	$\frac{V_1}{n_1} = \frac{V_2}{n_2}$	P, T

Example: Calculating the Energy of a Photon

• Given: Wavelength $\lambda = 500 \ \text{nm}$

• Find: Energy $E$

• Solution: $E = \frac{hc}{\lambda}$

• Convert $\lambda$ to meters: $500 \ \text{nm} = 5.00 \times 10^{-7} \ \text{m}$

• Plug in values: $E = \frac{6.626 \times 10^{-34} \ \text{J} \cdot \text{s} \times 2.998 \times 10^8 \ \text{m/s}}{5.00 \times 10^{-7} \ \text{m}} = 3.97 \times 10^{-19} \ \text{J}$

Additional info:

• This reference sheet is designed to provide quick access to essential constants, equations, and the periodic table for use in general chemistry problem solving and exam preparation.