Key Point for Chapter 14

( General Chemistry II )

Ch 14 :

1. Reaction Rate ===> Speed ==> Mf -Mi / Tf - Ti

2. Both Reactant ( disappearance ) and Product (appearance) must be

positive

3. Comparison of Rates :

Rule 1 : The bigger the coefficient, the faster the rate.

Rule 2: Reactant's coefficient UP / Product's coefficient DN

4. Prediction of Rate Law

Rate = k [A]m[B]n

k : rate constant

m and n : reaction order

m + n ::: overall reaction order.

5. Calculation to Determine the Reaction order m, n by experimental data.

6. Time Dependent Concentration Calculation

a. first order ( m + n =1 )

Ln[M]t = Ln[M]0 -- Kt

b. second order ( m + n = 2)

1/[M]t = 1/[M]0 + kt

c. half life

t1/2 = 0.69/k ( 1rt oredr )

t1/2 = 1/k[M]0 (2nd order)

7. Reaction Rate , Activation Energy and Catalyst

8. Reaction Mechanism: single step and multiple. Molecularity.

Slow step is rate determined step.