enthalpy

Question 1

define enthalpy of combustion

Answer 1

the enthalpy change needed for 1 mole to undergo complete combustion. all products and reactants must be in their standard states and conditions

Question 2

defien enthalpy of formation

Answer 2

the enthalpy change needed for 1 mole of compound to form from its elements. all products and reactants must be in their standard states and conditions

Question 3

define enthalpy

Answer 3

the energy change of a substance held at a constant pressure

Question 4

define hess’ law

Answer 4

the enthalpy of a reaction is independent of the route taken. it is only dependent upon the the intial and final energy stores.

Question 5

why is there sometimes a dip in enthalpies of combustions ( the number)

Answer 5

incomplete combustion
insufficient heat
compounds are impure and do not match up to values in books

Question 6

what can be done to prevent incomplete combustion

Answer 6

insulation
provide heat
good ventilation