Energy in chemical reactions Flashcards
endothermic reaction
one that takes in heat eg sherbet with water
exothermic reaction
one that gives out heat eg. burning coal
Collision Theory
for a reaction to occur, the reacting particles must collide with each other
effective collision
one that results in the formation of products when the activation energy is reached
Activation energy
the minimum energy which colliding particles must have for a reaction to occur
effect of heat on chemical reactions , explained
At a higher temp, colliding particles move more quickly
so they have more energy
so the amount of effective collisions is increased
so chemical reactions are faster
energy profile diagram
a graph that shows the change in energy of a reaction, as time passes, while the reaction takes place
how does a catalyst work
provides an alternative route for the reaction to occur which has a lower Activation Energy , so the rate of reaction increases
why would a graph be endothermic
if the energy of the products is higher than the energy of the reactants
traingle H
delta (change) in heat
whats the symbol used for activation energy
EA
small activation energy means..
a large number of molecules have enough energy to pass over this energy barrier, so the rate of reaction is quick
