General Chemical Relationships
in that compound that is being oxidized or reduced:
Molecular weight
.
.
- - - - - - - = gram-eqmvalent weIght
Change in valence
361
The normality of a standard solution is the ratio of the weight in grams of the
substance in 1 liter to the gram-equivalent weight:
Weight in grams per liter
1. ( )
------:------:-.-:--- = norma Ity N
Gram-equivalent weIght
Solutions of equal normalities are equal in their reaction potential, volume per
volume. For example, a volume of 0.1 N hydrochloric acid will react completely with
the same volume of 0.1 N sodium hydroxide. The use of normalities simplifies the
calculations necessary in obtaining the results of a volumetric analysis.
In routine analyses, such as those of oxygen, alkalinity, or dissolved CO 2 , there is a
general formula for the calculation of the appropriate correction factor when a
standard solution used in the titration procedure is of a normality other than that
specified:
Normality of solution used
. f b i · d
d
= correctlOn actor to e app Ie
Normality specifie
MOLAR SOLUTIONS
Molar concentration may be defined as the number of gram-moles of solute per liter of
solution. Then, a 1 molar solution (M) contains 1 g-mole of solute per liter of solution,
or 1 liter of aIM solution contains 1 g-mole of solute. Also 1 liter of a 2 M solution
contains 2 g-moles of solute, 1 liter of a 0.5 M solution contains 0.5 g-mole of solute, 2
liters of 1.5 M solution contains 3 g-moles of solute, and 0.5 liters of a 0.2 M solution
contains 0.1 g-mole of solute, or
or
(Number of liters of solution) x (molarity of solution)
= number of gram-moles of solute
Number of liters of solution x M = number of g-moles of solute
then
number of g-moles solute
M = number of liters solution
The molarity of a solution expresses the number of gram-moles of solute per liter of
solution.
STANDARD SOLUTIONS
Stock solutions should always be made more highly concentrated than those to be
used in the various determinations. Strong solutions usually change concentration less
upon storage than do weak ones. In preparing the standard solutions for use in the
in that compound that is being oxidized or reduced:
Molecular weight
.
.
- - - - - - - = gram-eqmvalent weIght
Change in valence
361
The normality of a standard solution is the ratio of the weight in grams of the
substance in 1 liter to the gram-equivalent weight:
Weight in grams per liter
1. ( )
------:------:-.-:--- = norma Ity N
Gram-equivalent weIght
Solutions of equal normalities are equal in their reaction potential, volume per
volume. For example, a volume of 0.1 N hydrochloric acid will react completely with
the same volume of 0.1 N sodium hydroxide. The use of normalities simplifies the
calculations necessary in obtaining the results of a volumetric analysis.
In routine analyses, such as those of oxygen, alkalinity, or dissolved CO 2 , there is a
general formula for the calculation of the appropriate correction factor when a
standard solution used in the titration procedure is of a normality other than that
specified:
Normality of solution used
. f b i · d
d
= correctlOn actor to e app Ie
Normality specifie
MOLAR SOLUTIONS
Molar concentration may be defined as the number of gram-moles of solute per liter of
solution. Then, a 1 molar solution (M) contains 1 g-mole of solute per liter of solution,
or 1 liter of aIM solution contains 1 g-mole of solute. Also 1 liter of a 2 M solution
contains 2 g-moles of solute, 1 liter of a 0.5 M solution contains 0.5 g-mole of solute, 2
liters of 1.5 M solution contains 3 g-moles of solute, and 0.5 liters of a 0.2 M solution
contains 0.1 g-mole of solute, or
or
(Number of liters of solution) x (molarity of solution)
= number of gram-moles of solute
Number of liters of solution x M = number of g-moles of solute
then
number of g-moles solute
M = number of liters solution
The molarity of a solution expresses the number of gram-moles of solute per liter of
solution.
STANDARD SOLUTIONS
Stock solutions should always be made more highly concentrated than those to be
used in the various determinations. Strong solutions usually change concentration less
upon storage than do weak ones. In preparing the standard solutions for use in the