Exo and Endo Reactions Flashcards
what is chemical energy
energy stored in the chemical bonds of a substance
making and breaking bonds involve loss and gain in energy
what is activation energy
energy required to break bonds in reactants for a chemical reaction to occur
what happens in endo and exo reactions
energy must be supplied to break the chemical bonds between the reactants
energy is released when new chemical bonds are made in products
exothermic energy supplied to released ratio
if more energy is released than supplied
endothermic energy supplied to released ratio
if more energy is supplied than released
how are chemical reaction classified
based on the type of heat change involved
exothermic - energy is released
endothermic energy is absorbed
endothermic reaction
more energy is taken into break bonds in the reactants than released by the bonds being formed in the products - energy is absorbed
heat is taken in
temperature of products drop
how to write endothermic reaction
reactants + energy/heat -> products
exothermic reaction
more energy is released when the products where formed than energy was used to break bonds in the reactants - net release of energy
heat energy is given off
temperature of the substances rises
how to write exothermic reaction
reactants –> products + energy/heat
examples of exo reactions
combustion of fuels
yeast and h2o2
epson salts and water
examples of endo reaction
photosynthesis
acetic acid + sodium bicarbonate
what is enthalpy
total amount of energy in a substnace
delta h = change in enthalpy of a chemical reaction
delta h = measure of how the enthalpy of the reactants is different to the products
enthalpy in ex o and endo
exo = delta H - (release)
endo = delta H + (absorbd)
