These are chemical reactions that give out heat so the temperature increases eg. coal burning to heat a room and fireworks exploding
Exothermic = energy exits
What is an endothermic reaction?
These are chemical reactions that take in heat causing a decrease in temperature eg. sherbet on your tongue and using an instant cold pack to reduce swelling
Endothermic = energy enters
What are energy profile diagrams?
These show energy transfers in chemical reactions
What is collision theory?
This happens before a chemical reaction when the particles in the reactants must collide with each other
The more collisions the faster the reaction will take place
Low concentration = few collisions
High concentration = more collisions
What is activation energy?
This is the minimum energy needed to start a reaction
What is meant by rate of reaction?
This describes how quickly a chemical reaction happens
Describe how temperature affects the rate of a reaction
Raising the temperature increases the rate of a reaction
As heat is added to a reaction, the particles that make up the reactants gain more kinetic energy and move faster
Describe how concentration of the reactants affects the rate of a reaction
Increasing the concentration of reactants increases the number of particles in a given volume
Low concentration results in fewer collisions
High concentration results in more collisions
Describe how surface area of the reactants affects the rate of a reaction
Increasing the surface area increases the rate of a reaction ie. as a particle size gets smaller, the surface area increases
If you cut a potato into smaller pieces it will cook quicker than cooking a whole potato
Describe how adding a catalyst affects the rate of a reaction
A catalyst speeds up the rate of a chemical reaction
It lowers the amount of energy needed for a reaction to happen which makes it easier for the particles to react so there is an increase in the rate of reaction