NEUTRALIZATION TITRATION Flashcards
is widely used to determine the concentration of acidic or basic analytes or analytes that can be converted to acids or bases by suitable treatment
Neutralization Titration
the usual solvent for neutralization titrations because it is convenient, inexpensive, and nontoxic -
it has a low-temperature coefficient of expression
Water
are widely used as standard solutions for titrating bases.
Hydrochloric acid solutions
most frequently used reagent for standardizing acids
Sodium Carbonate
most common base for preparing standard solutions
Sodium hydroxide
It is a nonhygroscopic crystalline solid with a relatively large molar mass (204.2 g/mol).
Potassium Hydrogen Phthalate (KHC8H4O4 )
It has limited solubility in water, so it is usually dissolved in ethanol prior to dilution with water and titration
Benzoic Acid
Is an excellent primary standard with a high molar mass per mole of protons.
Potassium Hydrogen Iodate KH(IO3 )2
Two Types of End Points in Neutralization Titration
Visual End Points
Potentiometric End Point
occurs in a wide variety of substances of interest in the life sciences, in industry, and in agriculture
Nitrogen
developed by the Danish chemist Johan Kjeldahl, who first described it in 1883
most common method for determining organic nitrogen
Kjeldahl Method
the sample is mixed with powdered copper(II) oxide and ignited in a combustion tube to give carbon dioxide, water, nitrogen, and small amounts of nitrogen oxides.
Dumas method
___ in organic and biological materials is conveniently determined by burning the sample in a stream of oxygen.
sulfur
are conveniently determined by conversion to ammonia with strong base followed by distillation.
Ammonium Salts
very common organic acids
Carboxylic and Sulfonic Acid Groups
generally have base dissociation constants on the order of 10-5 and can be titrated directly with a solution of strong acid.
Amine Groups
with aromatic characters, such as pyridine and its derivatives, are usually too weak for titration in aqueous solutions.
Cyclic amines
commonly determined by saponification with a measured quantity of standard base.
Ester Groups
s the process by which an ester is hydrolyzed in alkaline solution to give an alcohol and a conjugate base
Saponification
can be determined by esterification with various carboxylic acid anhydrides or chlorides
Hydroxyl Groups
Two Most Common Reagents
Acetic Anhydride
Phthalic Anhydride
Many aldehydes and ketones can be determined with a solution of hydroxylamine hydrochloride.
Carboxyl Groups
