Chapter 16.1
Specific Heat
Specific Heat
The specific heat of a substance is the heat required to raise the
temperature of one gram of that substance one degree centigrade.
Every substance has it’s own unique specific heat because every
substance is composed of different combinations of atoms.
The temperature of matter
is a direct measure of the
motion of the molecules;
the greater the motion,
the higher the
temperature:
Motion requires energy:
the more energy matter
has the higher the temp.
Typically this energy is
supplied by heat. Heat
loss or gain by matter is
equivalent energy loss or
gain.
Specific Heat
Water has a very high specific heat and it does not change
temperature quickly. Therefore, land masses that are close to large
bodies of water have a very moderate climate.
Common Specific Heats
Heat Absorbed and Released
Energy gained or lost by a substance is directly related to:
1. the mass
2. the change in temperature of that substance
Formula to calculate the values:
q = c x m x ∆T
q = heat released or gained
C = specific heat
m = mass
∆ = change in temperature
Specific Heat Practice Problems
1. A serving of Chubby Hubby Ice Cream contains
2675 kJ of energy. If you ate a serving of this ice
cream every night for four weeks and didn’t change
your diet and exercise routine, how much weight
would you gain in four weeks? ( One lb = 4000 Cal)
2. If the temperature of 50 g of ethanol increases from
21° C to 78.8° C, how much heat has been absorbed by
ethanol? (Specific heat for ethanol = 2.44 J/g°C)
Specific Heat Practice Problems
3. If the temperature of a 500 g piece of aluminum
increases from 20° C to 200° C, how much heat has been
absorbed by the aluminum? The specific heat of aluminum
is 0.897 J/g°C.
4. A 10.0 g nugget of pure gold absorbed 550 J of heat.
What was the final temperature of the gold if the initial
temperature was 21°C. The specific heat of gold is 0.129
J/g°C.