Controlling Reactions Flashcards
What is rate of reaction? Formula?
The rate of a chemical reaction is a measure of how quickly reactants are used or products are formed.
Rate === Quantity of reactant or product///Time Taken
What has to be the circumstances for a reaction to take place?
Reactants particles must collide with each other at the right orientation
The colliding particles must have enough energy to react
A collision that leads to a successful reaction is a successful collision
Factors that affect reaction rate
Temperature
Concentration
Surface Area
Pressure
Catalyst Presence
How does temperature affect reaction rate?
The higher temperature increases kinetic energy of particles so molecules move more colliding more frequently. Furthermore, a greater proportion of colliding particles have the activation energy or more.
How does surface area affect rate?
A larger surface area means a larger surface area to volume ratio and so more of the particles are exposed to the surface and able to react so frequency of collisions is higher
How do catalysts affect the rate of reaction?
Catalysts provide an alternative reaction pathway to reactants with a lower activation energy. So with a catalyst, a greater proportion of the colliding particles have the activation energy or greater and successful collisions are more frequent.
How does concentration or pressure affect rate of reaction?
With a greater concentration or pressure, there are more particles in the same given area and so collisions are more frequent.
What are the 2 types of catalysts?
Homogenous catalysts are the same physical state as the reactants.
Heterogenous catalysts are a different physical state as the reactants.
What are the commercial benefits of catalysts?
Catalysts are expensive upfront but save money over time.
Catalysts do not get used up.
Catalysts are used in small amounts.
Catalysts require less maintenance.
Catalysts produce less pollutants.
