Chemistry Revision Flashcards
1
Q
What is the rate of reaction?
A
- Refers to how fast a reaction takes place
- Shown by the change in concentration (of either products or reactants) per unit of time
2
Q
How do chemical reactions work on a molecular level?
A
- Reactions happen when particles collide with enough energy
- This causes the bonds between reactant molecules to break, allowing new bonds to form between atoms
3
Q
What factors affect the rate of reaction?
A
- Temperature: higher temperatures increase the rate of reaction by increasing the energy in which molecules collide with
- Concentration: increased concentration of dissolved reactants or increased pressure of gaseous reactant increases the frequency of particle collisions in a specific space
- Surface area: increased surface area of solid reactants makes more particles exposed to other reactants, allowing for a faster reaction rate of reaction
- Catalysts: they lower the activation energy, making it easier for molecules to react with each other, increasing rate of reaction
4
Q
What is activation energy?
A
It is the minimum energy required for particles to reaction. It varies based on the chemical reaction.
5
Q
What are catalysts and how do they work?
A
- Increase the rate of reaction without being used up
- Done by lowering activation energy
- Allows for product to be produced more quickly
6
Q
How can catalysts be used?
A
Note: other answers that are true are acceptable
- Products can be made more quickly due to faster ractions, saving time & money
- Reduces need for high temp. because of lower activation energy, saving fuel & reducing pollution
- Essential in living cells to keep you alive
7
Q
What does the rate of reaction depend on?\
A
- Frequency of collsions between particles: provides more opporunities to react
- Energy with which particles collide: higher energy means particles are more likely to exceed the activation energy needed to react
