CHEM 102 - Kinetics + Equilibrium

rate of reaction

• How fast reactants are converted to products.

rate law

• An equation showing how rate depends on concentrations

reaction order

• The power to which a reactant is raised in the rate law.

rate constant

• Proportionality constant in the rate law.

half-life

• Time for half of a reactant to react

integrated rate law

• Equation that gives concentration as a function of time

activation energy

• Minimum energy needed for a reaction to occur

arrhenius equation

• Shows how rate constant changes with temperature

collision theory

• Molecules must collide with:

  1. Correct orientation

  2. Sufficient energy ≥ Ea

reaction mechanism

• step-by-step sequence of elementary reactions

elementary reaction

• A single-step reaction with no intermediate

catalysts

• Substance that increases reaction rate without being consumed

chemical equilibrium

• A state where the rate of the forward reaction equals the rate of the reverse reaction.

equilibrium constant (K)

• Ratio of product concentrations to reactant concentrations at equilibrium, each raised to their stoichiometric powers.

reaction quotient

• Same as K but for any point in time, not necessarily equilibrium.

Le Chatelier’s Principle

• If a system at equilibrium is disturbed, it shifts to counteract the change.

ICE Table

I = Initial concentrations, C = Change, E = Equilibrium concentrations

• Tool to solve equilibrium problems

heterogenous equilibrium

• Equilibrium involving different phases (solid, liquid, gas)

Kp

• Equilibrium constant in terms of partial pressures of gases

endothermic vs exothermic reactions

• Endothermic (ΔH > 0): heat is a reactant → increasing T shifts right

• Exothermic (ΔH < 0): heat is a product → increasing T shifts left

shift

• Movement of equilibrium position in response to stress (change in Q, concentration, pressure, or temperature)

solubility product (Ksp)

• special K for slightly soluble salts