4.6- REPRESENTING THERMOCHEMICAL CYCLES Flashcards
1
Q
What can you use instead of thermochemical cycles to represent enthalpy changes in chemical reactions?
A
enthalpy diagrams
2
Q
What do enthalpy diagrams show?
A
energy (enthalpy) levels of reactants + products of chemical reaction on vertical scale, so can compare energies
3
Q
What do you say when a substance is of lower energy than another?
A
it’s energetically more stable
4
Q
What is the enthalpies of elements in their standard states taken as?
A
taken as zero
5
Q
In what forms can carbon exist in at room temperature? (3)
A
graphite
diamond
buckminsterfullerene (buckyballs)
6
Q
What are the forms that carbon can exist in at room temp called?
A
allotropes
7
Q
What is the most stable allotrope of carbon?
A
graphite- taken as standard state of carbon
