Application of Statistical and mathematical equations in Chemistry Part 1, Equivalent Weight Moles Molarity Normality Percent Concentration ppt, ppm, ppb for Solid &liquid Samples Concentration in (mequiv/L) Density

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Awad Nasser Albalwi
Application of Statistical and
mathematical equations in Chemistry
Part 1
Equivalent Weight
Moles
Molarity
Normality
Percent Concentration
ppt, ppm, ppb for Solid &liquid Samples
Concentration in (mequiv/L)
Density

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Awad Nasser Albalwi
Equivalent Weight theory:
Equivalent weight (also known as gram equivalent) is a term which has been
used in several contexts in chemistry. In its most general usage, it is the mass of
one equivalent, that is the mass of a given substance which will:
• supply or react with one mole of hydrogen cations H+
in an acid–base reaction; or
• supply or react with one mole of electrons e − in a redox reaction.
• Equivalent weight has the dimensions and units of mass, unlike atomic weight,
which is dimensionless. Equivalent weights were originally determined by
experiment, but (insofar as they are still used) are now derived from molar
masses.
• Additionally, the equivalent weight of a compound can be calculated by dividing
the molecular weight by the number of positive or negative electrical charges
that result from the dissolution of the compound.
equation:Equivalent weight
(g/equiv)no. of equiv = mass (g) / equiv.wt.
Moles theory:
A mole is the amount of pure substance containing the same number of chemical
). This2312 (i.e., 6.023 X 10-units as there are atoms in exactly 12 grams of carbon
thethe scale of atomic masses and--involves the acceptance of two dictates
magnitude of the gram. Both have been established by international agreement.
Formerly, the connotation of "mole" was "gram molecular weight." Current usage
number ofAvogadro'stends to apply the term "mole" to an amount containing
whatever units are being considered. Thus, it is possible to have a mole of atoms,
The Moles equation:ions, radicals, electrons, or quanta.
no. of moles = mass (g) / f. wt. (g/mol)
= mass (mg) / f. wt. (mg/mmol)no. of mmoles

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Awad Nasser Albalwi
The Molarity Theory
the molar concentration, is defined as the amount of a constituent ni (in moles)
divided by the volume of the mixture V . It is also called molarity (symbol M, in
moles per liter).
Applications of Molarity To determine the molarity of a solution, the number of
moles of solute added must be divided by the number of liters of total solution
produced.
If the amount of solute is given in grams, be sure to use the molar mass of the
solute to determine the number of moles in order to determine the molarity.
Molarity equation:
Molarity (M) = no.mole of solute / volume of solution (L)
Molarity (M) = no.mmole of solute / volume of solution (mL)
TheoryNormalityThe
Normality is a measure of concentration equal to the gramDefinition:
equivalent weight per liter of solution. Gram equivalent weight is the
measure of the reactive capacity of a molecule.
reaction determines the solution's normality.The solution's role in the
solution will have a normality (N) of 2 N4SO2For acid reactions, a 1 M H
ions are present per liter of solution.+because 2 moles of H
The Normality Formula
eq/Lsolution (L)Normality (N) = no. of equiv. / volume of
g/equiv)/moleequiv(equivno of. /MW (g/mol)=wtequiv

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Awad Nasser Albalwi
1-Ppt for for Solid / liquid Samples
Definition: Parts per thousand is a commonly used unit of concentration for
small values.
One part per thousand is one part of solute (g) per one thousand parts solvent (g)
3) ) * 10ppt (wt./wt.) = ( wt. of solute (g) / wt. of sample (g
Definition: Parts per thousand is a commonly used unit of concentration for
small values.
One part per thousand is one part of solute(g) per one thousand parts solvent (ml)
3ppt (wt./vol.) = ( wt. of solute (g) / wt. of sample (ml) ) * 10
2-Ppm for Solid & liquid Samples
Definition: Parts per million is a commonly used unit of concentration for small
values.
One part per million is one part of solute (g) per one million parts solvent (g)
ppm (wt./wt.) = ( wt. of solute (g) / wt. of sample (g) ) * 106
Definition: Parts per million is a commonly used unit of concentration for small
values.
One part per million is one part of solute(g) per one million parts solvent (ml)
ppm (wt./vol.) = ( wt. of solute (g) / wt. of sample (ml) ) * 106
3- Ppb for Solid & liquid Samples
Definition: Parts per billion is a commonly used unit of concentration for small
values.
One part per billion is one part of solute (g) per one billion parts solvent (g)
ppm (wt./wt.) = ( wt. of solute (g) / wt. of sample (g) ) * 109
Definition: Parts per billion is a commonly used unit of concentration for small
values.
One part per billion is one part of solute(g) per one billion parts solvent (ml)
ppm (wt./vol.) = ( wt. of solute (g) / wt. of sample (ml) ) * 109

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Awad Nasser Albalwi
Percent Concentration
1-Weight/Weight Percent Concentration, abbreviated as % (w/w)
In Latin "per cent" means "for every 100 hundred." When we express the
concentration of a solute in % (w/w), we are reporting the mass of solute for every
100 g of solution.
2- Volume /Volume Percent Concentration, abbreviated as % (v/v)
for every 100 hundred." When we express the concentration of a solute in % (v/v),
we are reporting the volume of solute for every 100 mL of solution.
2-Weight/Volume Percent Concentration, abbreviated as % (w/v)
In Latin "per cent" means "for every 100 hundred." When we express the
concentration of a solute in % (w/v), we are reporting the mass of solute for every
100 mL of solution.
Density & Specific Gravity of Solutions Theory:
Density Theory:
The density, or more precisely, the volumetric mass density, of a substance is
its mass per unit volume. The symbol most often used for density is ρ (the lower
case Greek letter rho).
Mathematically, density is defined as mass divided by volume:[1]
g/ml or kg/L
where ρ is the density, m is the mass, and V is the volume.

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Awad Nasser Albalwi
Specific gravity
Specific gravity is the ratio of the density of a substance to the density (mass of
the same unit volume) of a reference substance. Apparent specific gravity is the
ratio of the weight of a volume of the substance to the weight of an equal volume of
the reference substance. The reference substance is nearly always water for liquids
or air for gases. Temperature and pressure must be specified for both the sample
and the reference. Pressure is nearly always 1 atm equal to 101.325 kPa.
Temperatures for both sample and reference vary from industry to industry. In
British brewing practice the specific gravity as specified above is multiplied by
1000.[1] Specific gravity is commonly used in industry as a simple means of
obtaining information about the concentration of solutions of various materials
such as brines, hydrocarbons, sugar solutions (syrups, juices, honeys,
brewers wort, must etc.) and acids
True specific gravity can be expressed mathematically as:
where is the density of the sample and is the density of water.
The apparent specific gravity is simply the ratio of the weights of equal volumes
of sample and water in air:
where represents the weight of sample and the weight of
water, both measured in air.
It can be shown that true specific gravity can be computed from different
properties: