1. Rate of reaction =
Changes in amount of reactant/product
Decrease in amount of reactant Time taken Increase in amount of product
Suitable measurable
changes:
ZnCO3(s) + 2HCl(aq) ZnCl2(aq) + CO2(g) + H2O(l) Colour
Mass of Mass of Concentration
Concentration of ZnCO3 / g Volume of gas ZnCl2 / g Temperature
HCl / moldm-3 CO2/cm3 Volume of gas
Mass
Precipitation
Pressure
Time/s Time/s Time/s Time/s
Average rate of reaction = Instantaneous Rate Of
Change in selected quantity Reaction
MEASURING RATE OF REACTION = the gradient of the graph
Time taken at any given time.
Volume of
Volume of gas/ cm3
gas/ cm3 solution
Average rate of reaction in first
50 seconds
= Volume at 50 seconds
45
Time taken
= 30/50
40
=0.6 cm3 s-1 ( 45 – 20 ) - Plot a graph
( 45 – 20 ) - Draw a tangent
30
The average rate of reaction - Find the gradient
20
between 50 and 90 seconds ( 90 – 25 )
= V at 50 s – V at 90 s 18
Time taken
= (40-30)/(90-50) Time/ s
= 0.25 cm3 s-1 Time/ s 25 50 90
25 50 90
The rate of reaction at 50 second
= the gradient of tangent to the curve at the given
High Rat e of reaction
The average rate of reaction = 40 -Fast reaction, short time
time
for the whole reaction 90 = ∆ y cm3
Low Rate of reaction
= 0.444 cm3 s-1 ∆xs
-Slower reaction, long time
= 45 - 20
90 - 25
= 0.0345 cm3 s-1

2. Factors affecting rate of reaction
SIZE TEMPERATURE PRESSURE
Reaction When pressure
When total surface When temperature
has stopped increase rate of
area larger, rate of increases, rate of
reaction increase reaction increase reaction
increase
CONCENTRATION CATALYST
When concentration When positive
of reactant increase catalyst are used.
Gradient in reaction I steeper > Gradient rate of reaction rate of reaction
Gradient at t1 steeper > Gradient at t2 in reaction II increase
Rate of reaction t1 >Rate of reaction t2 Rate of reaction I >Rate of reaction II
Volume of
EFFECT OF THE SIZE OF REACTANT ON carbon dioxide/ cm3
RATE OF REACTION
CO2 CO2 gas
Gas
Experiment I
hydrochloric acid Aim : To investigate the effect of the size of reactant (small chip)
on the rate of reaction
Problem statement : How does the size of calcium
carbonate chips affect the rate of its reaction with Experiment II
calcium (large chip)
dilute hydrochloric acid?
carbonate
Hypothesis : The rate of reaction between calsium
Water carbonate and hydrochloric acid is increases when
smaller size calcium carbonate used
Time/s
Experiment I: 20 cm3 of 0.5 mol dm-3 Manipulated variable : The size of calcium carbonate
hydrochloric acid + excess of CaCO3 SMALL Responding variable : The rate of reaction • The rate of reaction in experiment II is higher than
CHIPS Fixed variables : Volume and concentration of HCl experiment I because the gradient of the graph II is
greater than graph I throughout the reaction.
Experiment II: 20 cm3 of 0.5 mol dm-3 Observable Change: Volume of gas CO2 in every 30 s
hydrochloric acid + excess of CaCO3 LARGE • The rate of reaction of the small calcium carbonate
CHIPS chips is higher compared than large calcium
The number of mole of HCl in both experiments: carbonate chip
Equation: = MV/1000
2CaCO3 + 2HCl CaCl2 + H2O + CO2 = 22 x 0.5)/1000 • The maximum volume of carbon dioxide gas
=0.01 mol collected for both experiments are equal because
the no. of mole of hydrochloric acid are the same

3. CONCENTRATION Volume of carbon dioxide/ cm3
Eye
Experiment I: 50 cm3 of 0.2 mol dm-3 sodium
thiosulphate solution + 5 cm3 of 0.5 mol dm-3 Exp I (high concentration)
hydrochloric acid
Sodium thiosulphate Experiment is repeated four times using 0.2 mol dm-3
solution sodium thiosulphate solution diluted with different Exp II
+ Hydrochloric acid volume of distilled water (Low concentration)
‘X’ Equation:
mark Na2S2O3 + 2HCl 2NaCl + S + SO2 + H2O
Observable Change: Yellow precipitate formed.
Experiment 1 2 3 4 5 - The rate of reaction in exp I is
higher than exp II
Aim : To investigate the effect concentration of sodium Volume of 0.2 - Exp I has higher concentration
thiosulphate on the rate of reaction moldm-3 Na2S2O3 , 50 40 30 20 10 than Exp II
V1 cm3 - Gradient I is steeper than
Problem statement : How does concentration of
Volume of distilled graph II
sodium thiosulphate affect on the rate of reaction 0.0 10 20 30 40
water added/cm3 - The maximum volume of
Volume of 1.0 mol carbon dioxide gas collected
Hypothesis : When concentration of sodium 5.0 5.0 5.0 5.0 5.0
HCl acid added/cm3 for both experiments are
thiosulphate increase, rate of reaction will increase.
Concentration of equal
0.2 0.16 0.12 0.08 0.04
Na2S2O3/moldm-3 - no. of mole of hydrochloric
Manipulated variable : concentration of sodium
Time taken/s 20 23 32 46 95 acid are the same
thiosulphate
Responding variable : The rate of reaction 1/time , s-1 0.05 0.043 0.031 0.022 0.011
Fixed variables : Volume and concentration of HCl -
Concentration of
Na2S2O3 (mol dm-3) Concentration is directly
Concentration of proportional to 1/time. Experiment 1:
Na2S2O3 (mol dm-3) Concentration is inversely 2.0 g Magnesium + 50 cm3 of
[ 1/time shows the rate of 2.0 mol dm-3 hydrochloric
proportional to time.
acid
reaction ]
When the concentration of
When the concentration of Experiment II
Na2S2O3 increases, a shorter 2.0 g Magnesium + 50 cm3 of
Na2S2O3 increases, the rate of 1.0 mol dm-3 hydrochloric
time is needed for marked
reaction is increase acid
across to disappear.
Ionic Equation: 1/time (s-1)
S2O3 2- + 2H+ S + SO2 + H2O
Time /s

4. Equation: Ionic Equation: Experiment 1:
Na2S2O3 + 2HCl 2NaCl + S + SO2 + H2O S2O3 2- + 2H+ S + SO2 + H2O 2.0 g Magnesium + 50 cm3 of
1.0 mol dm-3 hydrochloric
acid at 25 oC
CONCENTRATION TEMPERATURE
Eye Experiment II
Eye
2.0 g Magnesium + 50 cm3 of
Observable changes: 1.0 mol dm-3 hydrochloric
acid at 60 oC
Time required for mark
Sodium thiosulphate ‘X’ disappear from view. Sodium thiosulphate
solution solution
Volume of H2
+ Hydrochloric acid + Hydrochloric acid
/ cm3
Experiment is repeated four times using 0.2 ‘X’
‘X’
mol dm-3 sodium thiosulphate solution diluted mark Exp II (60 oC)
mark
Paper with different volume of distilled water Paper
sheet sheet Exp I
Concentration of (25 oC)
Na2S2O3 (mol dm-3) Experiment 1 2 3 4 Temperature
Na2S2O3 (mol dm-3)
Temperature/oC 30 40 50 60
Volume of 0.2
50 40 30 20 When temperature
When the concentration moldm-3 Na2S2O3 , Time /s
increase, Shorter time increase, Shorter time
Volume of distilled
is needed for mark ‘X’ 0.0 10 20 30 is needed for mark ‘X’ lower gradient
water added/cm3
disappear. disappear. :. Lower rate
Volume of 1.0 mol
5.0 5.0 5.0 5.0
HCl acid added/cm3
Concentration of Steeper gradient
0.2 0.16 0.12 0.08 :. Higher rate
Na2S2O3/moldm-3
Time taken/s 20 23 32 46 Volume of H2
1/time , s-1 0.05 0.043 0.031 0.022 / cm3
Time /s Time /s Exp I
Concentration of (high concentration)
Na2S2O3 (mol dm-3) Temperature
concentration of Na2S2O3 increase Na2S2O3 (mol dm-3) Temperature of Na2S2O3 increase
the rate of reaction increase the rate of reaction increase Exp II
(low concentration)
Time /s
Experiment 1:
2.0 g Magnesium + 50 cm3 of 1.0 mol dm-3
hydrochloric acid
1/time (s-1) 1/time (s-1) Experiment II
2.0 g Magnesium + 50 cm3 of 1.0 mol dm-3
Shows the rate of reaction sulphuric acid

5. Properties of catalyst
Decomposition Need a small amount
H2O2 2 H2O + O2 Specific in action
Chemically unchanged
AMOUNT OF CATALYST Does not affect amount
PRESENCE OF CATALYST product
Increase rate of
Problem statement : How does the amount reaction
Problem statement : How does the presence of of catalyst affect the rate of composition of
Observable changes:
catalyst affect the rate of composition of hydrogen peroxide solution?
The presence of oxygen
gas, tested with glowing hydrogen peroxide solution?
Hypothesis : When amount of catalyst used Observable changes:
wooden splinter
Hypothesis : Presence of catalyst increase the increase, the rate of decomposition of Volume of gas carbon
rate of decomposition of hydrogen peroxide hydrogen peroxide increase dioxide in every 30 s is
recorded
Experiment 1: Manipulated variable : Mass of catalyst
Decomposition of 50 Manipulated variable : Presence of catalyst
Responding variable : The rate of reaction Responding variable : The rate of reaction
cm3 of 1.0 mol dm-3 Fixed variables : temperature, volume and
Hydrogen Peroxide Fixed variables : temperature, volume and
concentration of hydrogen peroxide concentration of hydrogen peroxide
Experiment 1:
Experiment II Decomposition of 50
Decomposition of 50 cm3 of 1.0 mol dm-3
cm3 of 1.0 mol dm-3 Hydrogen Peroxide +
Hydrogen Peroxide + 0.5 g manganese (IV)
1.0 g manganese (IV) oxide
oxide
Experiment II
Decomposition of 50
Volume of O2 cm3 of 1.0 mol dm-3
/ cm3 Hydrogen Peroxide +
1.0 g manganese (IV)
Exp II Volume of O2 oxide
(with catalyst) / cm3
Exp II
Exp I (1.0 g MnO2) When amount Manganese(IV)
(without oxide increase , rate of reaction
catalyst) increase
Exp I
Total volume for both exp I and II
(0.5 g MnO2)
Time /s same
Because the molarity and volume
Lower gradient of hydrogen peroxide in both
:. Lower rate Manganese(IV) oxide act as catalyst reaction are same
Time /s
to increase rate of reaction Quantity of catalyst does not affect
Total volume for both exp I and II same Lower gradient the total volume of produced
Steeper gradient Because the molarity and volume of :. Lower rate
:. Higher rate hydrogen peroxide in both reaction are
same Steeper gradient
:. Higher rate

6. The Collision Theory Endothermic
reaction
Energy
Energy
Achieved a Ea
Right Exothermic
Molecule ust minimun Ea
collide orientation of amoun of reaction
collision energy (Ea) Product
”
reactants Ea
. Ea
’
products
The collisions that lead to a chemical reaction are known as
effective collisions Reactant
Reactant Progress of reaction
Progress of reaction
Explanation using Collision Theory
Energy Profile Diagram And Activation Energy, Ea’:
Ea – The minimum energy the reactant
SIZE CONCENTRATION TEMPERATUR
TEMPERATURE CATALYST Ea’ – The lower activation energy in the presence
of a catalyst.
The higher the The higher the Catalyst provides
The smaller the size concentration of temperature, the an alternative path Haber Process (NH3)
of reactant, the reactants, the higher is the kinetic of reaction which Iron, Fe
larger is the total higher is the energy of reacting needs lower
surface area number of particles particles. The activation energy
exposed to collision in a unit volume. reacting particles (Ea’) Uses of Ostwald process (HNO3)
move faster. Catalyst in Platinum, Pt
Industrial
Contact process (H2SO4)
Vanadium (V) oxide,
The frequency of collision between particles increases. V2O5
The frequency of effective collision between particles increases Cooking of solid food in smaller size
The total surface area on a smaller cut pieces of food is larger
The food can absorbed more heat.
The rate of reaction increases.
The time taken for the food to be cooked is shorter
me
Cooking in a pressure cooker
The high pressure in pressure cooker increases the boiling Storage of food in a refrigerator
point of water to a temperature above 100 °C. When the food kept in refrigerator, the food lasts longer
t
The kinetic energy of the particles in the food is higher
higher. The low temperature in the refrigerator slows down the
Time taken for the food to be cooked is decrease activity of the bacteria.
Thus the food cooked faster at a higher temperature in a The bacteria produce less toxin ,
pressure cooker. the rate of decomposition of food becomes lower

7. FACTOR EXPLANATION DIAGRAM
Volume of
Size
H2/ cm3
Size of zinc in exp. II is smaller than exp I.
Total surface area exposed to collision in exp.
Exp I: II is larger than exp. I
2 g of Zinc chip + 50 cm3 1.0 The frequency of collision between zinc and
mol dm-3 HCl hydrogen ion in exp II is higher Exp II
Frequency of effective collision between zinc
Exp II : and hydrogen ion in exp II is higher
2 g of Zinc powder + 50 cm3 1.0 Rate of reaction in exp. II is higher Exp I
mol dm-3 HCl
Time/s
Concentration Volume of H2
Concentration of hydrochloric acid in exp. II is / cm3
higher than exp I
Exp I: 2 g of Zinc powder + 50 The number particles per unit volume in exp. Exp II
cm3 0.5 mol dm-3 HCl II is higher than exp. I
Exp II : 2 g of Zinc powder + 50 The frequency of collision between zinc and
cm3 1.0 mol dm-3 HCl hydrogen ion in exp II is higher
Exp II
Frequency of effective collision between zinc
and hydrogen ion in exp II is higher
Rate of reaction in exp. II is higher
Time /s
Experiment I and II
Exp I use ethanoic acid (weak acid) and exp II use
hydrochloric acid (strong acid)
The number of hydrogen ions per unit volume Volume of H2
in exp. II is higher than exp. I / cm3
Concentration The frequency of collision between zinc and
hydrogen ion in exp II is higher
Frequency of effective collision between zinc Exp III
Exp I: 2 g of Zinc powder + 50 and hydrogen ion in exp II is higher
cm3 1.0 mol dm-3 CH3COOH Rate of reaction in exp. II is higher Exp II
Exp II : 2 g of Zinc powder + 50
cm3 1.0 mol dm-3 HCl
Exp III : 2 g of Zinc powder + 50 Experiment II and III Exp I
cm3 1.0 mol dm-3 H2SO4 Exp III use sulphuric acid (diprotic acid) and exp
II use hydrochloric acid (monoprotic acid)
The number of hydrogen ions per unit volume Time /s
in exp. III is higher than exp. II
The frequency of collision between zinc and
hydrogen ion in exp II is higher
Frequency of effective collision between zinc
and hydrogen ion in exp II is higher
Rate of reaction in exp. II is higher

8. Volume of
Temperature carbon dioxide/ cm3
Temperature of exp. II is higher than exp I.
Exp I: The kinetic energy of reactant in exp II is higher
2 g of Zinc chip + 50 cm3 1.0 than I
mol dm-3 HCl at 25 oC The frequency of collision between zinc and
Exp II
hydrogen ion in exp II is higher
Exp II : Frequency of effective collision between zinc
2 g of Zinc powder + 50 cm3 1.0 and hydrogen ion in exp II is higher
mol dm-3 HCl at 40 oC Rate of reaction in exp. II is higher Exp I
Time/s
Catalyst Volume of H2
Exp II use copper (II) sulphate act as catalyst / cm3
Exp I: Catalyst provides an alternative path of reaction Exp II
2 g of Zinc powder + 50 cm3 0.5 which needs lolower activation energy (Ea’) (with catalyst)
mol dm-3 HCl The frequency of collision between zinc and
hydrogen ion in exp II is higher
Exp II : Frequency of effective collision between zinc Exp I
2 g of Zinc powder + 50 cm3 1.0 and hydrogen ion in exp II is higher
mol dm-3 HCl and 2cm3 of Rate of reaction in exp. II is higher
copper (II) sulphate
Time /s
HAK MILIK SLM 2011