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Molarity

Molarity is a way to express the concentration of a solute in a solution. It is defined as the number of moles of solute per liter of solution and is denoted by the letter M. The unit is moles per liter (mol/L).

The molarity M is calculated from the amount of solute (in moles) and the total volume of

Preparing solutions with a known molarity typically involves weighing the appropriate amount of solute and dissolving

Examples: To make 1.000 L of 0.500 M NaCl, one needs 0.500 moles of NaCl, which is

Molarity is widely used in laboratory work for solution preparation, titrations, and quantitative analyses.

the
solution
(in
liters)
using
the
formula
M
=
n
/
V,
where
n
is
the
number
of
moles
of
solute
and
V
is
the
final
volume
of
the
solution
in
liters.
The
volume
used
in
this
calculation
refers
to
the
finished
solution,
not
just
the
solvent.
Because
volume
can
change
with
temperature,
molarity
is
temperature
dependent,
whereas
molality
(moles
of
solute
per
kilogram
of
solvent)
is
not.
it
in
a
solvent,
then
diluting
to
a
precise
final
volume
in
a
volumetric
flask.
For
a
desired
concentration
M2
in
volume
V2,
the
required
amount
of
solute
can
be
determined
by
n
=
M2
×
V2.
If
starting
from
a
stock
solution
with
concentration
M1,
the
relation
M1V1
=
M2V2
(dilution
equation)
allows
calculation
of
how
much
stock
solution
to
use.
about
0.500
×
58.44
g
=
29.22
g,
dissolved
and
diluted
to
a
final
volume
of
1.000
L.
To
prepare
0.500
L
of
a
0.111
M
glucose
solution
(molar
mass
~180.16
g/mol),
weigh
10.0
g
of
glucose,
dissolve,
and
dilute
to
0.500
L.