# Rates of Reaction

• Created by: ramyaa09
• Created on: 05-02-17 08:19
Finding the rate of reaction
Amount of reactants/time or Amount of products/time
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Finding the rate of reaction at a certain time
Find the Tangent-Draw a straight line which only touches that point. Find the gradient of the two points which the line touches.
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Change in y/ change in x
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What controls the rate of reaction?
Reactions take place when particles collide with a certain amount of energy.
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Activation Energy
The minimum amount of energy needed for particles to react is called the activation energy.
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The Rate of reaction depends on...
The frequency of collisions between particles and the energy with which the particles collide with.
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Particles will not react when...
the particles collide with energy less than the activation energy. The particles will just bounce of each other.
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Explain using a particle theory, the affect of increasing the temperature.(3)
Particles have more energy, collide more, more successful collisions will take place because they have activation energy, kinetic energy increases meaning the particles move faster
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Explain the affect of increasing the concentaration of reactant on the reaction.
More reactant particles in the same volume, more collision, increase in concentration
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Explain the affect of increasing the pressure of a reaction.
same number of reactant particles in a smaller volume,particles are closer together meaning more collisions.
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Explain the affect of using powdered reactant in the reaction.
more reactant particles are exposed to the other reactant, more collisions.
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Explain how a catalyst affects the rate of reaction.
A catalyst lowers the activation energy therefore increasing the frequency of successful collisions. The particles will move faster meaning the rate of reaction increases.
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Catalyst
A material that increases the rate of reaction but is not used up
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How does a catalyst work?
It lowers the activation energyfor a reaction therefore increasing the frequency of successful collisions.
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Everyday catalysts
Nickel is a catalyst in the production of margarine. Iron is catalyst in the production of ammonia from nitrogen and hydrogen. Platinum is a catalytic converters of car exhausts.
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Required Practical
Hypothesis:The rate of reaction depends on the concentration of reactants
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Required Practical
Dependant-The time taken for the magnesium to dissolve. Independant-the concentartion of HCL(25cm3) Control-the size of the magnesium(0.5cm)
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Required Practical
Higher the concentration means there are more reactant particles present therefore a greater frequency of collisions so the rate of reaction will increase.
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Reversible Reaction
A reversible reaction is one where the products of the reaction can themselves produce the original reactants.
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Reversible Reaction
The forward reaction-endothermic and the backward reaction-exothermic
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Equilibrium
If a reversible raection takes place in a closed system then a state of equlibrium can be met.
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Definition of equilibrium
When the amounts of reactants and the products reach a balance - their concentartion stop changing.
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Definition of closed system
None of the reactants or products can escape.
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Equilibrium is reached when...
the forward reaction and backward reaction are taking place at exactly the same rate.
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Yield
The more reactant that is used, the more product is made.
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Increasing yield-Temperature
If the temperature of a system at equilibriumis increased: the relative amount of products at equilibrium increases for an endothermic and decreases for exothermic.
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## Other cards in this set

### Card 2

#### Front

Finding the rate of reaction at a certain time

#### Back

Find the Tangent-Draw a straight line which only touches that point. Find the gradient of the two points which the line touches.

### Card 4

#### Front

What controls the rate of reaction?

### Card 5

#### Front

Activation Energy