Pygmalion: Act V & Postscript Quiz & Class Discussion Transformation: Of Two Kinds and More…
Discussion on rate of reaction =for quiz 1 and 2
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what is? Effectiv e collisio Collisi on theory? Factors affectin g? Activati on energy? Energy level diagram? Rate of reaction
description
Transcript of Discussion on rate of reaction =for quiz 1 and 2
what is?what is?
Effective collision?Effective collision?
Collision theory?Collision theory?
Factors affecting?Factors affecting?
Activation energy?Activation energy?
Energy level diagram?Energy level diagram?
Rate of reactionRate of reaction
AVERAGE RATE OF REACTION
For the whole exp
From X
min to Y min
On the X min (2nd) ( from 2nd to 1st)
For first x
(3) min( from 0 to
3rd )
b) Example from the graph, determine:i) The average rate of reaction for the
whole experiment =
Total volume of gas Total time taken
0
10
20
30
40
50
60
70
80
0 30 60 90 120 150 180 210 240 270 300
Volu
me
of g
as/
cm3
Time/ s
= 46 = 0.20 cm3 s-1
210
b) Example from the graph, determine:i) The average rate of reaction from 3
minute to 1 minute =
Total volume of gas at 3min -1 minTotal time taken at 3min -1min
0
10
20
30
40
50
60
70
80
0 30 60 90 120 150 180 210 240 270 300
Volu
me
of g
as/
cm3
Time/ s
= 44-25 = 0.13 cm3 s-1
180-60
b) Example from the graph, determine:i) The average rate of reaction for on
the 3rd minute=
Total volume of gas at 3min – at 2min Total time taken at 3min – at 2 min
0
10
20
30
40
50
60
70
80
0 30 60 90 120 150 180 210 240 270 300
Volu
me
of g
as/
cm3
Time/ s
= 44-38 = 0.10 cm3 s-1
180-120
b) Example from the graph, determine:i) The average rate of reaction for for
the first 2 minutes=
Total volume of gas at 2min – at 0min Total time taken at 2min – at 0 min
0
10
20
30
40
50
60
70
80
0 30 60 90 120 150 180 210 240 270 300
Volu
me
of g
as/
cm3
Time/ s
= 38-0 = 0.33 cm3 s-1
120-0
INSTANTANEOUS RATE OF REACTION
( rate of reaction at that time) Draw tangent to the
graph
Y
X
Rate = Y/X
b) Example from the graph, determine:i) The rate of reaction at 120 s
Instantaneous rate of reaction= Draw tangent to the graph
0
10
20
30
40
50
60
70
80
0 30 60 90 120 150 180 210 240 270 300
Volu
me
of g
as/
cm3
Time/ s
= 56 – 20 = 0.176 cm3 s-1
222-18
II
IIII
Volume of gas
Time
• Use positive catalyst• Increase temperature •Increase total surface area (TSA)•Increase conc but not the mole of reactant
• decrease temperature •Decrease TSA•Decrease conc but not the mole of reactant
Example: Sketch curve that would be obtained with the changes below:
originalLower temp
Volume of gas
Time
Lower temperature is used
Example: Sketch curve that would be obtained with the changes below:
original
higher temp
Volume of gas
Time
Higher temperature
Example: Sketch curve that would be obtained with the changes below:
originalBigger size
Volume of gas
Time
Bigger size of reactant is used
Example: Sketch curve that would be obtained with the changes below:
original
Smaller size
Volume of gas
Time
Smaller size of reactant
Example: Sketch curve that would be obtained with the changes below:
original
higher temp
Volume of gas
Time
Higher temperature
Example: Sketch curve that would be obtained with the changes below:
original
With catalyst
Volume of gas
Time
Catalyst was added
Changes to the FLAT part of graph
Example:Curve I represents the result of the experiment using excess zinc powder and 50cm3 of 1.0 moldm-3 dilute hydrochloric acid
I
Volume of gas/ cm3
Time/s
Draw curves when condition change:ORIGINAL: 50cm3 of 1.0 moldm-3 dilute hydrochloric acid Change : 50cm3 of 2.0 moldm-3 dilute hydrochloric acid
ori
Volume of gas/ cm3
Time/s
Change
Draw curves when condition change:ORIGINAL: 50cm3 of 1.0 moldm-3 dilute hydrochloric acid Change : 50cm3 of 0.5 moldm-3 dilute hydrochloric acid
ori
Volume of gas/ cm3
Time/s
Change
Draw curves when condition change:ori :50cm3 of 1.0 moldm-3 dilute hydrochloric acid change : 50cm3 of 0.5 moldm-3 dilute hydrochloric acid
ori
Volume of gas/ cm3
Time/s
change
Draw curves when condition change:ORI : 50cm3 of 1.0 moldm-3 dilute hydrochloric acid change : 20cm3 of 1.0 moldm-3 dilute hydrochloric acid
ori
Volume of gas/ cm3
Time/s
change
Draw curves when condition change:ori: 50cm3 of 1.0 moldm-3 dilute hydrochloric acid change: 25cm3 of 2.0 moldm-3 dilute hydrochloric acid
ori
Volume of gas/ cm3
Time/s
change
1. The effect of size of reactant
•Reducing the size of reactant
•increases the Total Surface Area
•increases the frequency of collisions between particles
•Increase the rate of reaction.
•Increase the frequency effective collisions between particles
2. The effect of temperature
•Increase the temperature of solution
•increase the kinetic energy of particles
•increase the frequency of collisions between particles
•Increase the rate of reaction.
•Increase the frequency effective collisions between particles
3. The effect of concentration•Increase the concentration of solution
•increase the number of particles per unit volume
•increase the frequency of collisions between particles
•Increase the rate of reaction.
•Increase the frequency effective collisions between particles
4. The effect of catalyst
•Catalyst provides alternative route
•That has a lower activation energy
•Increase the rate of reaction.
•So more particles have energy equal or greater than activation energy.
•Number of effective collisions increase.
exothermic reaction
Activation energy with catalyst
Activation energy no catalyst
reactant
Write chemical equation ( 9m)•Calcium carbonate and hydrochloric acid ( 2m)
OHCO
CaClHClCaCO
22
23 2
Write chemical equation ( 9m)•Sodium thiosulphate and sulphuric acid( 2m)
OHSOSOSNa
SOHOSNa
2242
42322
Write chemical equation ( 9m)•Decomposition of hydrogen peroxide ( 2m)
2222 22 OOHOH
What is the catalyst used in the decomposition hydrogen peroxide?(1m)
Manganese (IV) oxide
Write ionic equation for Sodium thiosulphate and sulphuric acid (2m)
OHSOSOSNa
SOHOSNa
2242
42322
OHSOS
HOS
22
232 2
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