oat chem unit 9

half life of my face is face years in jail

kinetics

determines how fast a reaction will happen without depending on spontaneity.

reaction rate

• Δ[A] / ΔT

• [A] = concentration of A

• T = time

• Time will be multiplied by the stoichiometric coefficient

reaction rate example

rate laws

• Rate = k[A]^m[B]ⁿ

• k = rate constant

• [A] & [B] = concentration of reactants

• n and m = reaction orders

• Products do not appear in rate law

• k, m, and n must be determined experimentally

• Overall reaction order = m+n

Temperature, catalyst, and concentration effects on rate and rate constant

zero order reaction

• Rate of the reaction does not depend on the concentration of the reactants.

• Rate = k[A]⁰ = k(1) = k

• Unit: k = M/s

first order reaction

• The rate of the reaction is proportional to the concentration of the reactant.

• Rate = k[A]¹ = k[A]

• Unit: k = 1/s

second order reaction

• For A → B: The rate of the reaction is proportional to the square of the concentration of reactant A.

  • Rate = k[A]²

• For A + B → C + D: The rate of reaction is proportional to both reactant A and B

  • Rate  = k[A][B] or k[A]² or k[B]²

• Units = 1/Ms

concentration vs time

determining rate law from experimental data

• To determine the rate order of A, use two trials in which [B] is equal.

• Divide concentrations of A (0.4 / 0.2 = 2)

• Divide initial rates (4.0E-5 / 1.0E-5 = 4)

• Rate = k[A]^x[B]^y ← solve for x

• When A is doubled, the rate is quadrupled → 2^x = 4 → x = 2

• Reaction order with respect to A: k = [A]²

• Do the same for B

integrated rate law

Determines the amount of reactant/product present over a period of time.

rate determining step

the slowest step of the reaction which determines the rate.

• This is the step with the highest activation energy.

• Determines the overall rate law.

intermediate

Formed during the reaction but are not part of the reactants or products.

catalyst

Lowers the activation energy, which increases the reaction rate. They are not consumed during the reaction (shows up in both reactants and products)

collision theory

For a chemical reaction to occur, three conditions must be met:

• Molecules must collide

• Molecules must have proper orientation when they collide

• Molecules must have sufficient energy to overcome the E_a barrier.

arrhenius equation

half life

time it takes to convert half of a reactant to product

• Zero order: lower concentration = lower half life

• First order: half life is independent of concentration

• Second order: lower concentration = higher half life

the

a determiner placed before nouns (and noun phrases) to indicate that the listener or reader already knows, identifies, or is already familiar with the specific person, place, thing, or concept being discussed