]]>
LearnNext
Get a free home demo of LearnNext

Available for CBSE, ICSE and State Board syllabus.
Call our LearnNext Expert on 1800 419 1234 (tollfree)
OR submit details below for a call back

clear

Integrated Rate Equations: Zero And First Order Reactions

8,114 Views
Have a doubt? Clear it now.
live_help Have a doubt, Ask our Expert Ask Now
format_list_bulleted Take this Lesson Test Start Test

Integrated Rate Equations: Zero And First Order Reactions - Lesson Summary

Using the differential rate equation and rate law, the rate of the reaction in terms of the rate of disappearance of reactant A is

Rate = - d[A]/dt = k[A]n

Zero order reactions:

Reactions in which the rate of reaction doesn't depend on the concentration of the reactants are called zero order reactions.

The integrated rate equation for a zero order reaction is,

        - d[A]/dt = k
     ∫ d[A] = - k ∫ dt
         [A] = -kt + C
 C = Constant of Integration

Initial Concentration [A] = [A]o at t = 0
                              [A] = -kt + C
                              [A]o = -k x 0 + C
                               C = [A]o    
                              [A] = -kt + C
   C =  [A]o
[A] = -kt + C
[A] = -kt + [A]o

Ex: Photochemical reactions are zero order reactions. Certain enzymatic reactions are also zero order reactions.

                      hv 
    H2 + Cl2      →     2HCl

                         hv
6CO2 + 6H2O    → C6H12O6  +  6O2

              Pt,1130 k
2NH3          →           N2 + 3H2
           High Pressure

       Δ
2HI →  H2  + I2
      Au


First order reactions:

A reaction in which the rate of reaction is proportional to the first power of the concentration of the reactant is called a first order reaction.

The integrated rate equation for a first order reaction is

- d[A]/dt = k[A]n
- d[A]/dt = k[A]
∫ d[A]/[A] = -k ∫ dt

loge[A] = -kt + C
[A] = [A]0, at t = 0
loge[A]0 = -k x 0 + C
C = loge[A]0

loge[A] = -kt + loge[A]0

k = 1/t . loge([A]0/[A])
loge = 2.303 log10
k = 2.303/t log10 ([A]0/[A])

Comments(0)

Feel the LearnNext Experience on App

Download app, watch sample animated video lessons and get a free trial.

Desktop Download Now
Tablet
Mobile
Try LearnNext at home

Get a free home demo. Book an appointment now!

GET DEMO AT HOME