# Rates of reactions

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What is the rate of a reaction?
The speed or how fast it is
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How can the rate of a reaction be measured?
Rate of reaction= Amount of reactant used or product formed/time
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What does the gradient or slope of the line on a graphy of amount of reactant of products againts time tell us?
The rate of the reaction at that time
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The steeper the gradient....
The faster the reaction
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What does the collision theory state?
Reactions can only happen if particles collide 9they must collide with enough energy to change into new substances)
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What is activation energy?
The minimum energy particles need to react
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Why does the rate of reaction increase if the surface area of any solid reactants is increase?
this increases the frequency of collisions between the reacting particles as there is more space
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Why does the temperature affect the rate of reaction?
increasing the temperature increases the speed of the particles in the reaction (have a higher kinetic energy) which means the particles collide more frequently
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Why does the concentration affect the rate of reaction?
a higher concentration means more atoms and molecules increasing the frequency of collisions between the particles and so increasing the rate
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Why does the pressure affect the rate of reaction?
increasing the pressure for gases is the same as increasing the pressure for liquids, the volume is smaller so the particles have less space and therefore collide more frequently
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Explain the reaction of sodium thiosulfate solution and hydrochloric acid
When they react sulfur is formed, sulfur is insoluable in water, the lenght of time it takes for the solution to go cloudy at different temps can be measured
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What is the effect of a catalyst?
Catalysts lower the of activation energy of the reaction allowing the substance to react at a lower temperature which decreases the amount of energy needed allowing it to react faster
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When and why are catalysts used?
Catalysts are mainly used in industrial processes as they manage to speed up the rate of reactions. they do this by lowering the activation energy which means they can use less energy to complete the reaction.This reduces costs - useful to companies
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## Other cards in this set

### Card 2

#### Front

How can the rate of a reaction be measured?

#### Back

Rate of reaction= Amount of reactant used or product formed/time

### Card 3

#### Front

What does the gradient or slope of the line on a graphy of amount of reactant of products againts time tell us?

### Card 4

#### Front

The steeper the gradient....

### Card 5

#### Front

What does the collision theory state?