Kinetics ❮ 211● (^) The half-life can be related to concentration and time by these two equations (first and
second order, respectively): t ==
kk
ln 2 0.693
1/2
and t1/2 = 1/k[A ] 0.
● (^) The activation energy is the minimum amount of energy needed to initiate or start a
chemical reaction.
● (^) Many reactions proceed from reactants to products by a series of steps called elementary
steps. All these steps together describe the reaction mechanism, the pathway by which
the reaction occurs.
● (^) The slowest step in a reaction mechanism is the rate-determining step. It determines the
rate law.
● (^) A catalyst is a substance that speeds up a reaction without being consumed in the reaction.
● (^) A homogeneous catalyst is in the same phase as the reactants, whereas a heterogeneous
catalyst is in a different phase from the reactants.