Bond Energies

Question 1

what happens to reactants and what happens to products in a reaction

Answer 1

breaks bonds of reactants (requires energy)

forms bond bewtween products (releases energy)

Question 2

what is bond energy

Answer 2

amount of energy required to break one mole of a particular covalent bond

Question 3

what is the state for endo thermic reactions

Answer 3

if more energy is required to break bonds than is needed to form bonds, energy is absorbed

Question 4

what is the state for exo thermic reactions

Answer 4

if more energy is released when products form that the amount requried to break bonds between reactants, energy is released

Question 5

what is the formula for enthalpy

Answer 5

energy products - energy of reactants (it is the total energy is a system)

Question 6

what does the law of conservation of energy state

Answer 6

if energy in a system falls than there will be a corresponding rise in the energy of surrounding because it is constant

Question 7

draw a potential energy graph for exo and endo

Answer 7

exo = reactants > products
endo  = reactants < products

Question 8

what 5 exo thermic reactions

Answer 8

comubustion
single atoms bond tog
electrons gained by pos ion
g>l, L>S
respiration

Question 9

wgar are 4 endo thermic reactions

Answer 9

molecules broken to form single atoms
atom lose electrons
s>l, l>g, s>g
photosynthesis