Specific Heat Capacity
Chu Wei Xiang (3S311)
Kenneth Tan (3S209)
Tan Yu Yang (3S323)
Specific Heat Capacity
• The amount of heat energy required to
raise the temperature of a unit mass (of
the body) by one degree, without going
through a change in state
Specific Heat Capacity
Q
c=
m × ∆T
Specific heat
capacity (in Jkg-1K-1
or Jkg-1 °C -1 )
Heat or thermal
energy absorbed
or released (in J)
Change in
temperature (final
temperature –
initial
temperature)
[in K or °C]
Mass of the substance
(in kg)
Specific heat capacity
• Larger amount of heat energy is required
to raise the temperature of a substance
with high specific heat capacity than one
with low specific heat capacity.
• The specific heat of almost any substance
can be measured, these includes chemical
elements, compounds, alloys, solutions
etc.
Factor affecting specific heat
capacity
• Impurities:
• For alloys, small impurity concentrations
can greatly affect the specific heat.
• Alloys may display difference in behavior
even when small amounts of impurities are
present on one element of the alloy.
Specific heat capacity and heat
capacity
• Temperature of an object is a measure of
its random molecular motions.
• Temperature increases as the average
speed of the atoms or molecules
increases.
• Different materials have different specific
heat capacity because different types of
molecules and atoms need different
amounts of energy to raise their speed.
Specific heat capacity and heat
capacity
• For the similar material, a larger object will
have a larger heat capacity
• More molecules that must move faster
to increase the temperature.
• Therefore they need more thermal
energy to raise the temperature.
List of specific heat capacities
Substance
c in J/gm K
c in cal/gm K or
Btu/lb F
Molar C
J/mol K
Aluminum
0.900
0.215
24.3
Bismuth
0.123
0.0294
25.7
Copper
0.386
0.0923
24.5
Brass
0.380
0.092
...
Gold
0.126
0.0301
25.6
Lead
0.128
0.0305
26.4
Silver
0.233
0.0558
24.9
Tungsten
0.134
0.0321
24.8
Zinc
0.387
0.0925
25.2
Mercury
0.140
0.033
28.3
Alcohol(ethyl)
2.4
0.58
111
Water
4.186
1.00
75.2
Ice (-10 C)
2.05
0.49
36.9
Granite
.790
0.19
...
Glass
.84
0.20
...
Specific Heat Capacity and
Heat exchanger
If the fluid passing through the pipes is to be
warmed:
 Fluid to be warmed: low SHC
 Fluid used to warm: low SHC
 Pipes (fluid to be warmed passes through):
low SHC
References:
• http://www.lifetimereliability.com/Training/TGT001%20Heat%20exchanger%20basics.pdf
• http://hyperphysics.phy-astr.gsu.edu/HBASE/thermo/spht.html#c2
• http://www.economicexpert.com/a/Joule:per:kilogram:kelvin.htm
• http://dic.academic.ru/dic.nsf/enwiki/17444
• http://physics.suite101.com/article.cfm/specific_heat_capacity
• http://www.absoluteastronomy.com/topics/Specific_heat_capacity
• http://books.google.com.sg/books?id=SEs6b6W3N4C&pg=PA195&lpg=PA195&dq=specific+heat+capacity+in+he
at+exchanger&source=bl&ots=R5lnhqoqbh&sig=SW568rWgY3pLDaEpR
YVsDInh2Y&hl=en&ei=Q7oCSvfoNsyGkQXoorzOBA&sa=X&oi=book_resu
lt&ct=result&resnum=7