Heat Capacity
Heat capacity (C) of a substance is “the quantity of heat
needed to raise the temperature of a substance by one degree Celsius (or one Kelvin).”
The heat capacity differ from substance to substance. The amount of substance
is directly proportional to the heat capacity. That means by doubling the mass
of substance, heat capacity can be doubled.
C = QΔ/Δt
Where the QΔ is the amount of heat required with
the change or temperature 
.
Unit: The S.I unit of heat capacity is JK-1.
Specific Heat
Capacity
It can be defined as “the quantity of heat required to raise
the temperature of one gram of a substance by one degree Celsius (or one
Kelvin) at a constant pressure.”
Thus
if the ΔQ is the amount of heat added to raise the temperature of ‘m’ kg of a
substance through ΔT, then
ΔQ µ ΔT_________(a)
ΔQ µ m_________(b)
Combine both (a) and (b)
ΔQ µ m ΔT
ΔQ = c m ΔT
c = ΔQ/m ΔT
Where ‘c’ is the proportionality constant known as specific capacity of the substances.
Unit
The unit of specific heat is Jg-1oC-1.
Molar Specific Heat Capacity
Heat required to raise the one degree temperature of one mole of substances.
ΔQ = c m ΔT _______(1)
n = molar mass (m) / molecular mass (M)
n = m / M
m = Mn_______(a)
Put equation in (a) in (1)
ΔQ = c nMΔT
Where “Product of
Molecular mass (M) and specific heat
capacity “c” is equal to Molar specific heat capacity ‘C”.
C = Mc
Then the equation
‘2’ will be
ΔQ = nC
C = ΔQ / n ΔT
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