A decrease in the concentration of reactants per unit time
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What 3 things must be present for a reaction to occur?
Molecules must collide, Molecules must be in the correct orientation and molecules must have enough energy to break bonds. Energy greater than activation energy
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How does increasing temperature increase the rate of a reaction?
Increasing temperature increases the average kinetic energy of the molecules. The numbers of collisions increase and there are more successful collisions as molecules have an energy that is greater than the activation energy
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How does increasing the concentration increase the rate of a reaction?
There are more particles per unit volume so the number of collisions increase and therefore by probability you get more successful collisions. However the rate of reaction decreases as the reactants get used up
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How does increasing pressure increase the rate of reaction?
There are more particles per unit volume so the number of collisions increase and therefore by probability you get more successful collisions
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How does increasing the surface area of solid reactants increase the rate of reaction?
Increasing the surface area increases the number of its particles that are available to collide with molecules so there are more sites for reaction
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How does a catalyst increase the rate of a reaction?
A catalyst lowers the activation energy without being chemically changed so that there are more successful collisions.
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Define activation energy
The minimum energy required for a reaction to occur
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Why does a small increase in temperature have a large effect on the rate of a reaction?
A small increase in temperature produces a large increase in the number of particles with energy greater than the activation energy. Therefore there are more successful collisions
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What are catalysts?
A substance that speeds up the rate of a chemical reaction without being chemically changed
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How do catalysts work?
Catalysts provide an alternative route for the reaction that has a lower activation energy.
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What are the two categories of catalyst?
Heterogeneous catalyst- where the catalysts is in different phase to the reactants. Homogeneous catalyst- where the catalyst and reactants are in the same phase
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Other cards in this set
Card 2
Front
What 3 things must be present for a reaction to occur?
Back
Molecules must collide, Molecules must be in the correct orientation and molecules must have enough energy to break bonds. Energy greater than activation energy
Card 3
Front
How does increasing temperature increase the rate of a reaction?
Back
Card 4
Front
How does increasing the concentration increase the rate of a reaction?
Back
Card 5
Front
How does increasing pressure increase the rate of reaction?
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