Test 4 Review Flashcards
stored energy
potential energy
feels hot
exothermic
releases heat
exothermic
delta H is positive
endothermic
absorbs heat
endothermic
feels cold
endothermic
reactants have heat
endothermic
heat is a product
exothermic
delta H is negative
exothermic
delta E symbolizes
internal energy
amount of heat required to melt 1 g of substance
heat of fusion
has more energy: boiling water v steam
steam
change in internal energy equation
delta E = Q + W (1st law of thermodynamics)
1 cal =
4.184 J
when work is done on system
positive
when entropy decreases
negative
gain in heat
positive
work is done by the system
negative
increase in entropy
negative
gain in heat
positive
under spontaneous conditions, if +delta S, then delta H is
negative (exothermic reaction)
enthalpy equation
delta H= delta E + PV
heat absorbed or released equation
Q = mc delta T
total amount of heat liberated from start of reaction to end
heat of reaction