Itprovidesa

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: porization).
So,
in
principle,
we
can
easily
determine
Sm
Ø(T)
if
we
know
 the
quantity
Sm
Ø(0)
and
if
we
can
find
a
way
to
estimate
the
heat
capacity
 of
the
solid
from
0
K
to
the
lowest
temperature
where
calorimetric
 measurements
are
made.

The
latter
issue
is
easily
resolved,
if
we
consider
 Marand’s
Notes:
Chapter
3
‐
The
Second
Law
of
Thermodynamics
 112
 the
result
of
a
theory
by
Peter
Debye,
which
states
that
at
low
 temperatures,
the
heat
capacity
of
pure
solids
is
given
by
CPm
=
a
T3.

The
 constant
“a”
is
easily
determined
by
fitting
experimental
molar
heat
 capacity
data
as
a
function
of
temperature
in
the
lowest
temperature
range
 accessible.
Heat
capacity
data
down
to
0
K
can
then
be
calculated
at
any
 temperature
using
the
value
of
“a”,
which
varies
from
substance
to
 substance.
 The
former
issue
concerning
the
value
of
the
molar
entropy
at
0
K
is
 addressed
by
the
Third
Law
of
Thermodynamics,
which
states
that:
 “If
the
entropy
of
any
element
in
its
pure
form
and
most
stable
state
at
 temperature
of
0
K
is
taken
as
0,
then
every
substance
has
a
positive
 entropy
which
at
T
=
0
K
may
become
zero
and
which
does
become
zero
 for
all
perfect
crystalline
substances,
including
compounds”.
 
 We
note
that
such
a
low
is
fully
compatible
with
the
very
famous
 Boltzmann
equation,
which
directly
associates
the
entropy
S
with
the
 concept
of
order/disorder.
 Boltzmann
stated
that
the
entropy
of
a
system
is
defined
by:
 S
=
k
ln(W)
 Marand...
View Full Document

This note was uploaded on 01/26/2014 for the course CHEM 3615 taught by Professor Aresker during the Spring '07 term at Virginia Tech.

Ask a homework question - tutors are online