enthalpy changes

Cards (14)

standard conditions for enthalpy change?
100kpa and 298k
what does a negative delta h mean?
exothermic reaction
what does a positive delta h mean?
endothermic reaction
what is enthalpy of formation? 
energy change when 1 mole of a substance is formed from its elements in their standard states
enthalpy change of combustion?
enthalpy change when 1 mole of a substance is completely burned in oxygen
enthalpy change of neutralisation?
enthalpy change when an acid and alkali react to form 1 mole of water
what happens in an endothermic reaction?
bond breaking
what happens in an exothermic reaction?
bond making
equation for enthalpy change? 
q=mcΔH
what is hess's law?
enthalpy change is independent to the route taken
which way do the arrows point in a formation hess cycle?
up
what direction do the arrows point in a combustion hess cycle?
Down
how to calculate ΔH from a formation hess?
sum of products - sum of reactants
how to calculate ΔH from a combustion hess?
sum of reactants - sum of products