18. RATES OF REACTION Flashcards
(10 cards)
Define Rate of reaction
The change in concentration of a reactant or a product in a given time
What is the rate equation?
rate = change in concentration / change in time
rate = moldm^-3s^-1
concentration = moldm^-3
time = s
What can the order of reaction be?
zero order (0)
first order (1)
second order (2)
When is a reaction zero order with respect to the reactant?
When the concentration of a reactant has no effect on the rate of reaction
When is a reaction first order with respect to the reactant?
When the rate depends on its concentration raised to the power of 1
When is a reaction second order with respect to a reactant?
When the rate depends on its concentration raised to the power of 2
What is a general rate equation?
rate = k[A]^m[B]^n
k = rate constant
[A] = conc of A
m = order of reaction with respect to A
[B] = conc of B
n = order of reaction with respect to B
How do you work out overall order?
Overall order = sum of orders with respect to each reactant
(m+n)
What are the units for concentration?
moldm^-3
What are the units for rate?
moldm^-3s^-1
