3.2 Energetics Flashcards
1
Q
exothermic
A
- heat given out
- releases energy in the form of heat
- forming chem bond releases energy
- products have less energy than reactants
- temp surroundings increase
2
Q
endothermic
A
- heat taken in
- absorbs energy in the form of heat
- breaking a chem bond requires energy
- usually feel cold - takes away heat
- products have more energy than reactants
- temp surroundings decrease
3
Q
exothermic example
A
- freezing
- condensation
- combustion
4
Q
endothermic example
A
- melting
- evaporation
- photosynthesis
5
Q
what is the ‘system’
A
reactants and products formed during reaction
6
Q
what is the ‘surrounding’
A
anything that’s not a reacting particle
7
Q
draw the energy level diagram for an exothermic reaction
A
8
Q
draw the energy level diagram for an endothermic reaction
A
9
Q
△H for exothermic reaction
A
negative
10
Q
△H for endothermic reaction
A
positive
11
Q
what is activation energy
A
minimum amount of energy needed to start a reaction
12
Q
what is the △H?
A
difference between energy needed to break bonds in reactants and energy given out when new bonds are made in product
13
Q
△H =
A
△H = mc△T
energy change = mass x specific heat capacity x temp change (of surroundings)
