Rate processes in chemical reactions Flashcards
What is the equation for rate of reaction?
rate = k [A]ᵐ [B]ⁿ
What is the RDS?
the slowest step in the reaction
If rate of reaction doubles when [reactant A] doubles…
the rate is 1st order with respect to A
If rate of reaction quadruples when [reactant B] doubles…
the rate is 2nd order with respect to B
What are orders of reaction equal to in stoichoimetric equations?
the coefficients
What is the equation for rate constant?
k = Ae⁻ᴱᵃᶴᴿᵀ
A is frequency factor e is base of natural logs Ea is activation energy R is ideal gas constant (1.99) T is the absolute temperature
What does an exothermic potential energy diagram look like?
products after curve are above reactants (+ΔH)
What does an endothermic potential energy diagram look like?
products after curve are below reactants (-ΔH)
What are catalysts?
Compounds that don’t directly participate in reactions but help to lower the activation energy
What is the rate of an enzyme catalysed reaction?
rate = k [ES]
What are saturation kinetics?
when [S] is large enough for substrate to occupy all available sites on enzyme, any further increase in [S] would have no effect on the rate of reaction
What is the equation to work out the rate constant K from a reversible reaction?
when aA + bB ⇌ cC + dD
K = [C]ᶜ[D]ᵈ / [A]ᵃ[B]ᵇ
What does Le Chatelier’s principle state?
A system in equilibrium will act to resist change in conditions
If there is an increase in concentration, where does equilbrium move?
products side
If there is an decrease in concentration, where does equilbrium move?
reactants side
