Group Work : Download
8/2/2011 : Given the group assignment.
SAMPLE ANSWER
Question 1 :
(i) Use zinc powder in excess. More total surface area of zinc atom exposed for collisions. Frequency of collision between zinc atom and hydrogen ion were increased. Frequency of effective collision between zinc atom and hydrogen ion also increased. Rate of reaction higher.
(ii) Zn + H2SO4 → ZnSO4 + H2
∴1 mol H2SO4 → 1 mol H2
no of mole H2SO4= 50 (2) / 1000 = 0.1 mol
∴0.1 mol H2SO4 → 0.1 mol H2
Volume of gas given off = 0.1 x 24 = 2.4 dm3
Showing posts with label collision theory. Show all posts
Showing posts with label collision theory. Show all posts
Wednesday, February 9, 2011
Sunday, January 30, 2011
collision theory continue...
We know that the particles of matter (solid, liquid, gas) are moving all the time. Solid just vibrate in fixed position, liquid move randomly-fast and gas move freely - faster.
Do you think that moving particles are collide each other?
See this video.
So what do you think. How is this movement and collision related to chemical reaction?
In chemical reaction, the substance reacted (reactant) and formed the new product. Let's consider from the equation below:
The particles of Zn (Zinc atom) and the particles of HCl (Hydrogen ion) must collide before they can react to form new substances which is ZnCl2 and H2.
Collisions must satisfy TWO CONDITIONS before they can result in reaction to form the product :
Why reactant particles MUST HAVE ENOUGH ENERGY ?
The man must have a strong force to push the rock to overcome the small hill
We can consider the small hill is barrier must be overcome, to push up the big rock over the barrier, the man must have more energy to push the rock.
In chemical reaction, barrier like as Activation Energy, Ea. Particles of reactant must have enough energy to overcome the Activation Energy, Ea. See an example video here.
What we can said ;
When Marble A have low energy, Marble A can't push Marble B and move down the slope together. (Marble A not enough energy - move slower - low kinetic energy) - insufficient energy
When Marble A have medium energy, Marble A can push Marble B(bounce) not move down the slope together.
(Marble A not enough energy - just rebound ) - insufficient energy
When Marble A have high energy, Marble A can push Marble B and move down the slope together.
(Marble A have enough energy - form new product) - sufficient energy
Energy content of reacting particles must be equal or higher than the Activation Energy of reaction.
See this video.
So what do you think. How is this movement and collision related to chemical reaction?
In chemical reaction, the substance reacted (reactant) and formed the new product. Let's consider from the equation below:
The particles of Zn (Zinc atom) and the particles of HCl (Hydrogen ion) must collide before they can react to form new substances which is ZnCl2 and H2.
Collisions must satisfy TWO CONDITIONS before they can result in reaction to form the product :
1. The colliding reactant particles must have enough energy.
2. The reactant particles must be oriented correctly when they collide.
Collisions that result in reaction between particles and formed the product called effective collision.
Refer : EFFECTIVE COLLISION or see collision theory by brightstorm
Why reactant particles MUST HAVE ENOUGH ENERGY ?
Lets look an analogy the man push up the big rock over the small hill.
The man must have a strong force to push the rock to overcome the small hill
We can consider the small hill is barrier must be overcome, to push up the big rock over the barrier, the man must have more energy to push the rock.
In chemical reaction, barrier like as Activation Energy, Ea. Particles of reactant must have enough energy to overcome the Activation Energy, Ea. See an example video here.
What we can said ;
When Marble A have low energy, Marble A can't push Marble B and move down the slope together. (Marble A not enough energy - move slower - low kinetic energy) - insufficient energy
When Marble A have medium energy, Marble A can push Marble B(bounce) not move down the slope together.
(Marble A not enough energy - just rebound ) - insufficient energy
When Marble A have high energy, Marble A can push Marble B and move down the slope together.
(Marble A have enough energy - form new product) - sufficient energy
Energy content of reacting particles must be equal or higher than the Activation Energy of reaction.
ENERGY CONTENT of reacting particles, Ec ≥ ACTIVATION ENERGY of reaction , Ea
WHAT IS ACTIVATION ENERGY?
Thursday, January 13, 2011
CHEMICAL REACTION
We know, the chemical reaction is process involve transformation of substance to form another substances.
Initial substances involved in reaction called REACTANT or REAGENTS
Final substances produce after reaction happened called PRODUCTS
# Example of reaction students learn in Chemistry is
i) Neutralisation : Reaction between Acid and Alkali.
ii) Displacement of Metal : Reaction of Electropositive metals and Salts Solution.
iii) Combustion : Burn the substances with oxygen in the air.
iv) Precipitation : Reaction to produce - Insoluble salts
According COLLISION THEORY :
1st : Reacting particles must collide each other ;
2nd : Have minimum required energy;
3rd : Collide in the correct orientation.
Effective Collision Occurs when reacting particles have enough energy and correctly oriented when they collide. Effective Collision of REACTANTS will formed the new PRODUCTS
- Chemical Reaction occurs...
Initial substances involved in reaction called REACTANT or REAGENTS
Final substances produce after reaction happened called PRODUCTS
# Example of reaction students learn in Chemistry is
i) Neutralisation : Reaction between Acid and Alkali.
ii) Displacement of Metal : Reaction of Electropositive metals and Salts Solution.
iii) Combustion : Burn the substances with oxygen in the air.
iv) Precipitation : Reaction to produce - Insoluble salts
HOW REACTION OCCUR?
According COLLISION THEORY :
1st : Reacting particles must collide each other ;
2nd : Have minimum required energy;
3rd : Collide in the correct orientation.
Effective Collision Occurs when reacting particles have enough energy and correctly oriented when they collide. Effective Collision of REACTANTS will formed the new PRODUCTS
- Chemical Reaction occurs...
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