enthalpy
what is enthalpy
total measure of increase or decrease of energy in a chemical reaction
what is it?
the time taken for a chemical reaction to occur
what is a physical change and example
when a substance changes state, but not its chemistry. it is reversible, ice melting or freezing
what is activation energy
minimum amount of energy required to start a chemical reaction
exothermic reaction
a reaction that releases energy into its surroundings
how to increase rate of reaction
increase temp, concentration, pressure, surface area or introduce a catalyst
what is a chemical change and example
when reactants in the original substance form new products, baking a cake
what happens when a catalyst is added to a chemical reaction
it lowers the activation energy
endothermic reaction
a reaction that absorbs energy from its surroundings
what is a chemical reaction
reactant particles colliding to form a new product, caused by the breaking and reforming of bonds between atoms
is the catalyst used up in the chemical reaction
no, it is not used up
describe an enthalpy diagram
blah blah blah
evidence of chemical reaction
color change, odour, change in temp, gas formed, precipitate formed
collision theory
in order for a chemical reaction to occur, particles must collide with enough energy and in the correct orientation