1. Zero Order of Reaction:
Experiment 8
Chemical Kinetics:
Zero Order of Reaction:
Iodination of Acetone

2. Theory:
A reaction is said to be of zero order if its rate is entirely independent of the concentration of the reactants

3. If the rate is independent of [A]  -dC/dt = k
Theory:
If the rate is independent of [A]  -dC/dt = k
k= 𝐶ₒ −𝐶 𝑡  t = 𝐶ₒ −𝐶 𝑘
When t = 𝑡  C = Cₒ 2
𝑡 = Cₒ − − Cₒ k = Cₒ −Cₒ k
𝑡 = Cₒ 2k
Where :
Cₒ: Initial Concentration
K: Rate Constant of Zero Order (Unit: 𝑴 𝑺 −𝟏 )
𝒕 𝟏 𝟐 : Half life time

4. Theory: C O
CH3
H3C
acetone
CH2I + I2
+ HI + H+ H+
Step (1)  (CH3)2C=O + H+   (CH3)2C=O+H
Slow
SLOW protonation of the aceton is the rate determining step.
Step (2)  (CH3)2C=O+H    CH3C(OH)=CH2 + H+
Fast
Step (3)  CH3C(OH)=CH2 + I2   CH3COCH2I + HI
Fast
If aceton is taken in large excess, its concentration may be taken to be constant
-d[I₂]/dt = k  d[I₂]= k dt  [I₂]= - k t + [I₂]ₒ
Where [I₂]ₒ : Initial concentration of I₂

5. 10 mL I2 (0.1N)
10 mL acetone
10 mL H2SO4(0.1N)
70 mL H2O

6. Na2S2O3 (0.004 N)
Starch indicator
Mixture of acetone, H2SO4, H2O and I2
10 mL of Mix.
5 mL NaHCO3

7. decrease Results: t, min. Vt ml of Na₂S₂O₃ [I2], N 3 6 9 12 15 18 2124 27 30
N X V (NaS₂O₃)= Nʹ x Vʹ(I₂)
[I₂] = Nʹ= N X V (NaS₂O₃) Vʹ
[I₂]=Nʹ= X Vt (Burtte) 𝟏𝟎
decrease

8. [I₂] = - k t + [I₂]ₒ y Slope X Intersept [I₂]ₒ [I₂], N 𝒕, 𝐦𝐢𝐧.
Graph:
Law of Zero Order of Reaction
[I₂] = - k t + [I₂]ₒ y
Slope X
Intersept
[I₂]ₒ
Intersept
Slope = - k
k= - 𝒔𝒍𝒐𝒑𝒆 = ?
Unit of k: 𝑵 𝒎𝒊𝒏. −𝟏
Intercept= [I₂]ₒ= ?, N
𝒕 𝟏 𝟐 = [I₂]ₒ 2k = ? 𝒎𝒊𝒏.
[I₂], N
Slope
𝒕, 𝐦𝐢𝐧.