CHAP. 9: CHEMICAL KINETICS [CONTENTS] 280
d) Type
aA +bB +cC→products, (9.50)
when there are three reactants with general stoichiometric coefficients and the partial orders
equal 1.
9.2.4.1 Type.
3 A→products (9.51)
9.2.4.2 Kinetic equation
−
dcA
dτ
=kAc^3 A. (9.52)
9.2.4.3 Integrated forms of the kinetic equation
For time as a function of the reactant concentration we write
kτ=
1
2
(
1
c^2 A
−
1
c^2 A0
)
. (9.53)
For the concentration of substance A as a function of time we write
cA=
cA0
√
1 + 2c^2 A0kτ
. (9.54)
9.2.4.4 Reaction half-life
τ 1 / 2 =
3
2 kc^2 A0
. (9.55)
9.2.4.5 Type.
2 A + B→products. (9.56)