Question

what are the units for the following:

the RATE of a chemical reaction, for k in a FIRST ORDER reaction, for k in a SECOND ORDER reaction, for k ZERO ORDER reaction

Answer 1

Zero-Order Reaction

For a zero-order reaction, the rate of reaction is a constant. When the limiting reactant is completely consumed, the reaction abrupts stops.

Differential Rate Law: r = k

The rate constant, k, has units of mole L^-1 sec^-1.

First-Order Reaction

For a first-order reaction, the rate of reaction is directly proportional to the concentration of one of the reactants.

Differential Rate Law: r = k [A]

The rate constant, k, has units of sec^-1.

Second-Order Reaction

For a second-order reaction, the rate of reaction is directly proportional to the square of the concentration of one of the reactants.

Differential Rate Law: r = k [A]²

The rate constant, k, has units of L mole^-1 sec^-1.