Changes
 Exothermic
vs
 Endothermic
Changes
 Exothermic
 Reaction that releases
heat
vs
 Endothermic-Absorbs
heat
Exothermic
Endothermic
making ice cubes
melting ice cubes
formation of snow in clouds
conversion of frost to water vapor
condensation of rain from water
vapor
evaporation of water
a candle flame
forming a cation from an atom in the
gas phase
mixing sodium sulfite and bleach
baking bread
rusting iron
cooking an egg
burning sugar
producing sugar by photosynthesis
Heat versus temperature
HEAT (q)
 Measure of the total
energy in a substance
 Sum of energy of all
particles(kinetic energy
and potential energy)
 Units: Joule (kgxm2/s2)
kJ
TEMPERATURE
 Related to the Average KE
of particles in a sample
 Units:
K or C
3 things that the quantity of heat
transferred are dependent on:
 Nature of the material changing
temperature
 Mass of the material changing temperature
 Size of temperature change
Specific heat
 Amount of energy needed to raise the temp of 1 g of a




substance 1 C (a calorie is the amount of heat required
to raise the temperature of 1 g of H2 O 1 C) 1 cal=4.184 J
Helps you to determine how many joules or calories it
takes a known mass of something to change from one
temperature to another
Symbol: cp
Unit: J/(g.K)
Formula: cp= q/mT
 q-amt of energy lost or gained
 m-mass
 T= temperature change