Essential Equations and Constants in GOB Chemistry

Essential Equations & Constants in GOB Chemistry

Gas Laws

Gas laws describe the relationships between pressure, volume, temperature, and amount of gas. These equations are fundamental in understanding the behavior of gases in chemical and biological systems.

• Ideal Gas Law: Relates pressure, volume, temperature, and moles of a gas. Equation: $PV = nRT$ P: Pressure (atm or Pa) V: Volume (L or m3) n: Number of moles R: Gas constant (0.0821 L·atm·mol-1·K-1 or 8.314 J·mol-1·K-1) T: Temperature (K)

• Combined Gas Law: Used when the amount of gas is constant but pressure, volume, and temperature change. Equation: $\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}$ P: Pressure V: Volume T: Temperature (K)

Dilution Calculations

Dilution equations are used to determine the concentration of a solution after adding solvent.

• Dilution Equation: Equation: $C_1 V_1 = C_2 V_2$ C: Concentration (M) V: Volume (L) 1: Initial 2: Final Example: If you dilute 10 mL of 1.0 M NaCl to a final volume of 100 mL, the final concentration is $C_2 = \frac{C_1 V_1}{V_2} = \frac{1.0 \times 10}{100} = 0.10$ M.

Acid-Base Equilibria

Acid-base chemistry is central to GOB Chemistry, especially in biological and environmental contexts.

• pH Equation: Equation: $\mathrm{pH} = -\log[\mathrm{H}^+]$ [H+]: Concentration of hydrogen ions (mol/L) Example: If $[\mathrm{H}^+] = 1 \times 10^{-4}$ M, then $\mathrm{pH} = 4$.

• Henderson-Hasselbalch Equation: Used for buffer solutions to relate pH, pKa, and the ratio of conjugate base to acid. Equation: $\mathrm{pH} = \mathrm{p}K_a + \log\left(\frac{[A^-]}{[HA]}\right)$ [A-]: Concentration of conjugate base [HA]: Concentration of acid pKa: $-\log K_a$, where $K_a$ is the acid dissociation constant Example: For a buffer with $[A^-] = 0.1$ M, $[HA] = 0.1$ M, and $pK_a = 4.75$, $\mathrm{pH} = 4.75$.

Electrochemistry

Electrochemical cells involve redox reactions and are important in energy conversion and biological systems.

• Cell Potential Equation: Equation: $E_{cell}^\circ = E_{reduction}^\circ - E_{oxidation}^\circ$ Ecell∘: Standard cell potential Ereduction∘: Standard reduction potential Eoxidation∘: Standard oxidation potential Example: If $E_{reduction}^\circ = 0.80$ V and $E_{oxidation}^\circ = 0.40$ V, then $E_{cell}^\circ = 0.40$ V.

Organic Chemistry: Alkane Nomenclature

Alkanes are saturated hydrocarbons with single bonds. Their names are based on the number of carbon atoms and branching.

• Parent Chain Names:

  Number of Carbons	Parent Name
  1	methane
  2	ethane
  3	propane
  4	butane
  5	pentane
  6	hexane
  7	heptane
  8	octane
  9	nonane
  10	decane

• Alkyl Groups:

  Number of Carbons	Alkyl Group Name
  1	methyl
  2	ethyl
  3	propyl
  4	butyl
  5	pentyl
  6	hexyl
  7	heptyl
  8	octyl
  9	nonyl
  10	decyl

• Example: 2-methylpropane is an alkane with a three-carbon chain and a methyl group attached to the second carbon.

Additional info:

• Some constants and equations were inferred and clarified for completeness.

• Organic nomenclature tables were reconstructed for clarity and academic context.