Chapter 18 Flashcards
How do you determine the rate if the reaction?
Rate = change in concentration of either products or reactants / change in time
What is the unit for concentration?
Mol dm-3 s-1
What is the order of reaction?
The ride of reactions determine the relationship between the rate of reactions and the concentration of the products and reaction
Rate ∝ [A] ^n
Common orders are zero, first and second order
What is zero order?
When the concentration of a reactant has no effect on the rate of the reaction, the reaction is zero order with respect to the reactant
Rate ∝ [A]^0
What is first order?
When the rate of the reaction depends on the concentration raised to the power of one, with respect to the reactant
Rate ∝ [A]^1
e.g. if conc on A doubles, the reaction rate increased by 2^1=2
What is second order?
When the rate of reaction is depends on the concentration raised to the power of 2, with respect to the reactant.
Rate ∝ [A]^2
e.g. if conc of A is doubled the reaction rate will increase by 2^2 = 4
What is the rate equation?
It gives the mathematical relationship between the concentrations of the reactants and reaction rate.
Rate = k [A]^m [B]^n
K = rate constant
What is the rate constant (k)?
The proportionality constant. It is the number that mathematically converts between the rate of reaction, concentrations and orders.
What is the overall order?
It gives the overall effect of the concentrations of all the reactants on the rate of reaction.
Overall order = sum of all the orders with respect to each reactant. (m + n)
