rates of reaction Flashcards
what is an exothermic reaction?
give an example
a reaction which gives out heat
handwarmers
what happens during an exothermic reaction?
the temperature increases
what is an endothermic reaction?
give an example
a reaction which absorbs heat from its surroundings
cooling pouches
what happens during an endothermic reaction?
the temperature decreases
what are signs of a chemical reaction?
- colour change
- solid forming
- gas given off
- energy change
large particle size means
small surface area
smaller particle size means
large surface area
how can you increase the rate of a chemical reaction?
- increase concentration
- increase temperature
- decrease particle size
- use a catalyst
what is a catalyst?
a substance that speeds up the rate of a reaction without being used up
how do you tell how fast the reaction is on a graph?
the steeper the curve the faster the reaction
how do you know when the reaction has stopped?
the curve becomes horizontal
