Pharma Ana finals Part 1

Titrimetric method of analysis

Defined as those analytical methods in which the volume of a solution of known concentraton consumed during an analysis is taken as a measure of the amount of active constituent of a sample.

Titration

It is used to determine the unknown concentration of an identified analyte (substance of interest)

The concentration of a basic solution

It can be determined by titrating it with a volume of a standard acid solution (of known concentration) required to neutralize it.

The purpose of titration

Is the detection of the equivalence point, the point at which chemically equivalent amts. Of the reactant

Simple titration

Back titration

Double titration

Volumetric analysis can be classified into 3 types:

Acid-base titration

Redox titration

Precipitation titration

Complexometric titration

Types of volumetric analysis

Analyte

Substance being analyzed. Usually the active ingredient of the preparation being analyzed.

Equivalence point

The theoretical point at which equivalent amt. Of each have reacted

Stoichiometric point

Other name for equivalence point

End point

The point where in the titration stopped, at which there occurs a sudden change in color in some property of the reaction mixture

Indicator

A chemical which changes colors or produce precipitate at a very near point of titration where equivalent quantities of analyte and titrant have reacted.

Molarity

Concentration of a solution in terms of moles of solute per liter

Normality

Number of equivalents of solute per liter or milliequivalents per milliliter of solution

Normality

It is the most usual concentration system because the reaction capability of the reagent or an analyte is taken into account when solutions are prepared.

Primary standard

The substance use to standardize a titrant, which is carefully weighed of known purity.

Standard solutions

Solutions of accurately known concentration

Primary standard

A substance of a known high degree of purity that undergoes one invariable reaction with the other reactant.

Secondary standard

A solution that has been titrated against a primary standard

Primary standard

Reagent which is very pure, generally representative of the number of moles the substance contains and easily weighed.

Primary standard

A reagent that's stable, it’s not a hydrate/has no water of hydration and has a high molecular weight

Primary standard

High level purity, low reactivity (high stability), high equivalent weight

Primary standard

Non hygroscopic, non toxic, inexpensive and readily available

Primary standard

Should be readily soluble under the condition in which is employed

Sodium carbonate NaCO3

Sodium tetraborate Na2B4O7

Potassium hydrogenphthalate KH(C8H4O4)

Potassium hydrogeniodate KH(IO3)2

Primary standard used in acid-base titration

Pure metals (zinc, copper, magnesium,and manganese) and salts

Primary standard used for complex Formation reaction

Silver

Silver nitrate

Sodium chloride

Potassium chloride

Potassium bromide

Primary standards used for Precipitation reaction

Potassium dichromate (K2Cr2O7)

Potassium bromate (KBr)

Potassium iodate (KIO3)

Sodium oxalate (Na2C2O4)

Pure Iron

Primary standards of Oxidation reduction reaction

Secondary standard

A chemical or reagent which has certain properties such as….

Less purity

Less stable and more reactive

Titrated against primary standard

And is somewhat hygroscopic

Secondary standard

Are commonly used to calibrate analytical methods.

Standardization

Determination of the normality or molarity of a solution

Standardization

The process by which the concentration of a solution is accurately determined by titrating with a primary standard.

Titration

The act of adding and measuring the volume of titrant used in an assay

Titrant

The solution of known concentration. Usually added by means of burette

Titer

Weight of the substance chemically equivalent to 1 ml of a standard solution

Hydrochloric Acid

Sulphuric acids

Secondary standard acids

Sodium hydroxide

Ammonia

Secondary standard bases

Potassium permanganate

Secondary standard oxidizing agent

Potassium acid phtalate

Oxalic acid

Benzoic acid

Sulphamic acid

Primary standard acid

Borax

Sodium carbonate

Primary standard base

Potassium dichromate

Potassium bromate

Potassium iodate

Primary standard oxidizing agents

Sodium oxalate

Arsenious and Potassium ferrocyanide

Primary standard reducing agent