Rates Flashcards
What does the rate of reaction indicate?
How quickly reactants are used up or products are formed
How do you calculate the mean rate of reaction?
Amount of product formed or reactant used / change in time
Gives a rate of reaction in g/s, cm/s or mol/s.
What is the method to calculate the rate at a specific point in time?
Draw a tangent to the line, expand into a right-angled triangle. Rate = rise/run.
What are the two main requirements for a reaction to occur according to Collision Theory?
Particles must collide and have enough energy to overcome activation energy
What happens to the rate of reaction as concentration or pressure increases?
Rate of reaction increases
Due to more particles per unit volume, more collisions, and more successful collisions per unit time.
What effect does increasing surface area have on the rate of reaction?
Increases Surface Area: Volume Ratio leading to more successful collisions per unit time
How does increasing temperature affect the rate of reaction?
Particles have more kinetic energy, leading to more collisions and a greater proportion of particles exceeding activation energy
Fill in the blank: The minimum amount of energy particles must have to react is called _______.
activation energy
True or False: A higher concentration of reactants always results in a slower reaction rate.
False
What do catalysts provide for reactions?
An alternative pathway with lower activation energy
This allows a greater proportion of particles to have energy greater than the activation energy.
How does the use of a catalyst affect the rate of reaction?
Increases the rate due to more successful collisions per unit time
What is a key characteristic of a catalyst during a chemical reaction?
It is not used up
Do different reactions require different catalysts?
Yes
What are enzymes?
Biological catalysts
What is an exothermic reaction?
A reaction that transfers energy to the surroundings, increasing their temperature
