C2.4 Rates And Energy Flashcards
How does concentration affect the rate of reaction?
The larger the concentration, the longer the rate of reaction
Why does concentration affect the rate of reaction?
If you increase the concentration, the reactant particles become more crowded and there is a greater chance of the particles colliding and therefore the rate of reaction increases.
The more particles there are the closer they will be together and this means the frequency of collisions increases and this speeds up the rate of reaction.
What’s activation energy?
The smallest amount of energy that particles must have before they react.
What’s the equation for rate of reaction?
Rate of reaction = amount of reactant used or amount of product formed / time
How does surface area affect the rate of reaction?
When a solid reacts in a solution, the size of the pieces of solid affect the rate of reaction. The particles inside the solid have to wait for the particles on the surface to react first. In smaller lumps, more solid is surrounded by the solution so reaction can take much faster.
How does temperature affect the rate of reaction?
Particles will collide more often
Particles collide with more energy
When you heat a substance up, energy is transferred to its particles so the particles move much faster. There will be more collisions so more opportunities to react meaning a faster rate of reaction. They gain more energy so move around faster meaning more collisions.
What’s a catalyst? How do catalysts affect the rate of reaction?
A catalyst is a substance that increases rate of reaction. It’s not used up in the reaction. They lower the activation energy so the reaction speeds up. Different catalysts are used for different reactions. They can be in many forms giving them the biggest surface area.
Why do catalysts lower the price of a reaction?
They give a bigger surface area which means lower temps and lower pressures are needed which lowers the amount of energy used which lowers the price.
What’s an exothermic reaction?
Energy is exiting the system to the environment (temperature will rise - it will feel hot)
What’s an endothermic reaction?
Energy is going into the reaction from the environment (temperature will drop - it will feel cold)
What’s the symbol for a reversible reaction?
______\
-—-
(Look it up :,))
Breaking bonds ______ __ energy
Making bonds ______ ____ energy
Takes in
Gives out
Anhydrous copper (II) sulphate + water -(reversible reaction sign)-> _____
Hydrated copper (II) sulphate
