Quiz 2 - Chemical Kinetics: Rate Laws | Chemical Kinetics: Rate Laws

A is a reagent and its stochiometric coefficient is 2. Reaction rate of a reagent:
 

The overall order of reaction is the sum of the orders of reaction of all the reactants

The rate of reaction is in mol.L^-1.s^-1 and [A]² [B] is in mol³.L^-3   ⇒    k is in mol^-2.L².s^-1

For a first-order reaction:   ${\mathrm{t}}_{1/2} = \frac{\ln 2}{\mathrm{k}}$

For a second-order reaction:   ${\mathrm{t}}_{1/2} = \frac{1}{\mathrm{k} {\left[\mathrm{A}\right]}_0}$

For a first-order reaction:   $- \frac{∆\left[\mathrm{A}\right]}{∆\mathrm{t}}$ = k [A]

After integrating:    ln [A] = ln [A]₀ - kt   ⇒   $\frac{\left[\mathrm{A}\right]}{{\left[\mathrm{A}\right]}_0}$ = e^-kt

The reaction rate is defined as the change in concentration of a reactant or product per unit time.

Radioactive decay generally follows first-order kinetics, where the rate of decay is proportional to the amount of substance present.

For a second-order reaction, the integrated rate law is $\frac{1}{\left[\mathrm{A}\right]}$ = $\frac{1}{{\left[\mathrm{A}\right]}_0}$ + kt, where k is the rate constant, [A]₀​ is the initial concentration, and [A] is the concentration at time t.

After 20 years (which is four half-lives), the fraction remaining is ${\left(\frac{1}{2}\right)}^4$ = $\frac{1}{16}$