PRESENTATION TOPIC NON AQUEOUS TITRATION

Submitted to : Ms farzana priyanka Dept of pharmacy South East university Submitted by: Fatiha zannat shashi ID:2013000300002 Sazeda khatun ID:2013000300003 Rawnak reza ID:2013000300006 Sumaiya deen ID:2013000300011 Alamin hossain ID:2013000300012 Akhi akhter ID:2013000300016

Definition of non aqueous titration Non aqueous titration are those titration in which titration of weak acidic or basic substance carried out using non aqueous substance.so has to get end point . Such titration can also be used for the titration of those substance which are not soluble in aqueous solvent. It provide a solvent in which organic compound are soluble. The most commonly used procedure is the titration of organic bases with perchloric acid in anhydrous acetic acid

Uses of non aqueous titration Non aqueous solvent are basically used for those acid or base (1) Which don’t give sharp end point in titration. (2) Which don’t soluble in water. Hence non aqueous titration is a titration of substance which dissolve in non aqueous solvent and it is suitable for weak acid and weak base

Acid-base reactions The theory is that water behaves as both a weak acid and a weak base; thus, in an aqueous environment, it can compete effectively with very weak acids and bases with regard to proton donation and acceptance, as shown below: H2O + H+ ⇌ H3O+ Competes with RNH2 + H+ ⇌ RNH3+ or H2O + B ⇌ OH- + BH+ Competes with ROH + B ⇌ RO- + BH+

Theory and role of solvent The role of solvent in making a substance and strongly weak acid and strongly weak base. Ex:-Like HCL in water is strong acidic. HCL in water is weak acidic. Acetic acid in water is weakly acidic where as acetic acid in ammonia is strongly acidic thus the acidic or basic character are depend on the uses of appropriate solvent. The non aqueous titration can be explained by the useing Bronsted-Lowry theory. According to this theory an acid is a proton donor and base is a proton acceptor

What is non aqueous titration solvent and its types Non aqueous solvent which are used in non aqueous titration are called non aqueous solvent. They are following types: Aprotic Solvent Protogenic Solvent Protophillic Solvent Amphiprotic Solvent

Aprotic solvent Aprotic solvent are most important solvent in this titration. This solvent are chemically inert and they work as a catalyst. Like this solvent are increase the rate of speed in reaction and also decrease the rate of speed in reaction during the chemical process or reaction it will depend on condition. The most important examples of aprotic solvent are • Chloroform • Benzene

Protogenic solvents Protogenic solvent are acidic in nature. And they can donate the proton, and they enhance the strength of weak bases. Examples of Protogenic solvent are HCL H2so4

Protophillic solvents Protophillic solvent are basic in nature. Which possess a high affinity for proton. Examples:- Liquid ammonia amines and ketone.

Amphiprotic solvents Amphiprotic solvent are those solvent they work as a both mean Protogenic or Protophillic. It means Amphiprotic solvent are acidic and basic in nature. And they are accept the proton and donate the proton. For examples:- Water Alcohols and weak organic acids

Detection of end point Visual indicator are formed to the most suitable for the detection of end point in non-aqueous titration. The important indicator used for non-aqueous titration are follow: Crystal voilet:- It is used as 0.5% solution in glacial acetic acid, it gives voilet • colour in basic medium and yellowish green in acidic medium. It is most widely use for the titration of pyridine with prechloride acid. Oracet Blue B Indicator:- It is prepared o.5% glacial acetic acid. It gives blue colour in basic medium while pink colour in acidic medium. Quinaldine Red Indicator:- It is used 0.1% solution in methenol/ethenol. Methenol is more stable. It gives yellow colour in basic medium while almost colourless in acidic medium.

Advantages of non aqueous solvent over aqueous solvents: Organic acids and bases that are insoluble in water are soluble in non-aqueous solvent. Organic acid, which is of comparable strength to water,can be titrated easily in non-aqueoussolvent. Bases also follow the same rules A non-aqueous solvent may help two are more acids in mixture. The individual acid can giveseparate end point in different solvent

Examples of non aqueous solvents By the proper choice of the solvents or indicator, the biological ingredients of a substance whetheracidic or basic can be selectively titrated. Non aqueous titrations are simple and accurate, examples of non aqueous titration are:Ephedrine preparations, codeine phosphate in APC, tetracycline, teramycin, Antihistamines andvarious piprazine preparations Examples of non aqueous solvents Glacial Ethanoic Acid Dimethylformamide Acetonitrile Dioxane Alcohol

Applications of non aqueous titration Although indicators may be used to establish individual end points, as in traditional acid-basetitrations, potentiometric methods of end point detection are also used extensively, especially forhighly coloured solutions. Non aqueous titration have been used to quantify the mixtures of primary,secondary and tertiary amines, for studying sulphonamides, mixture of purines and for many otherorganic amino compounds and salts of organic acid. And also it is used for the titration of Halogenacid salts of weak bases

Sl no Name of substance Indicator employed 1 2 3 4 5 6 7 8 9 10 11 12 Amantadine hydrochloride  Crystal violet 2 Chlorpromazine hydrochloride Methyl orange 3 Clonidine hydrochloride α-Naphthol benzein 4 Cyproheptadiene.HCl  5 Isoprenaline hydrochloride 6 Morphine sulphate do 7 Phenylephrine hydrochloride 8 Phenytoin sodium 9 Promethazine hydrochloride Methyl orange 10 Thiabendazole 11 Imipramine hydrochloride 12 Lignocaine hydrochloride 13 Dehydroemetine.HCl 14 Ephedrine hydrochloride 15 Morphine hydrochloride

Titration Curves The effect of this is that the inflection in the titration curves for very weak acids and very weak bases is small, because they approach the pH limits in water of 14 or 0 respectively, thus making endpoint detection relatively more difficult. A general rule is that bases with pKa < 7 or acids with pKa > 7 cannot be determined accurately in aqueous solution. Substances which are either too weakly basic or too weakly acidic to give sharp endpoints in aqueous solution can often be titrated in nonaqueous solvents.

Advantages of non-aqueous titration Enlargement of solubility range: many substances that are not soluble in water can be easily titrated in water-free media (e.g. fats and oils). Enlargement of application range: weak bases and acids can be easily titrated. Substance compositions that cannot be separately determined in aqueous media can often be titrated in non-aqueous media.

Disadvantages of non aqueous titration Most phenomena (like promoting and leveling as well as differentiating effects) of common nonaqueous titrations can be explained by the Brönsted's concept combined with the hydrogen bond theory but some open problems are shown in connection with the use of formic acid and/or acetic anhydride.

Reagents for titration in non-aqueous media Reagents for acid titration 1,2-Ethylenediamine Dimethylformamide (DMF) Isopropanol Acetone Reagents for base titration Acetic Acid Acetic anhydride methanol