Activity 6 | Rate Law

What are the units for the rate constant of a first order reaction and pseudo first order reaction?

s^-1

What are the units for the rate constant of a second order reaction and a mixed second order reaction?

M^-1s^-1

What are the units for the rate constant of a zeroth order reaction?

M s^-1

Rate Law

k[A]^x[B]^y

Rate Constant (k)

A constant of proportionality in the rate law equation, indicating how the reaction rate is related to the concentrations of reactants

Order of Reaction

The exponent to which the concentration of a reactant is raised in the rate law equation, indicating the degree to which the concentration of that reactant affects the reaction rate

Overall Reaction Order

The sum of the orders of all reactants in the rate law equation

Pseudo First Order Conditions

A method used to simplify a reaction with two reactants to behave as though it is first order by maintaining an excess of one reactant, making its concentration effectively constant

Mixed Second Order Reaction

A reaction where the order with respect to each reactant is one, resulting in an overall second-order reaction but with two distinct reactants

Beer’s Law

A = εcl

• A = absorbance

• ε = molar absorptivity

• c =concentration

• l = the path length of the sample (1)

First Order Reaction

A reaction where the rate is directly proportional to the concentration of one reactant

rate = k[A]

Second Order Reaction

A reaction where the rate is proportional to the square of the concentration of one reactant

rate = k[A]²

Zeroth Order Reaction

A reaction where the rate is independent of the concentration of the reactant

rate = k