Rates of reaction Flashcards
How can you work out the rate of a reaction?
Amount of reactant used or amount of product formed ÷ Time taken
When does the rate rate of reaction increase?
When the temperature is increased
If the concentration of a dissolved reactant is increased
When the pressure of a reacting gas is increased
If solid reactants are broken into smaller pieces
If a catalyst is used
What happens to reacting particles in a chemical reaction?
The reactant particles collide.
What is the activation energy?
The minimum energy needed for particles to react is called the activation energy.
Why does the rate of reaction increase if the concentration of a dissolved reactant or the pressure is increased?
There are more reactant particles in the same volume
There is a greater chance of the particles colliding
The rate of reaction increases
Why does the rate of reaction increase when a solid reactant is broken into smaller pieces?
Its surface area is increased
More particles are exposed to the other reactant
There is a greater chance of the particles colliding
The rate of reaction increases
Why does the rate of reaction increase when the temperature increases?
The reactant particles move more quickly
More particles have the activation energy or greater
The particles collide more often, and more of the collisions result in a reaction
The rate of reaction increases
How do catalysts increase the rate of reaction?
Catalysts increase the rate of reaction without being used up. They do this by lowering the activation energy needed. With a catalyst, more collisions result in a reaction, so the rate of reaction increases. Different reactions need different catalysts.
Why are catalysts useful in industry?
Because they reduce costs
