ACID-BASE TITRATION

ACID-BASE TITRATION

PHARMACEUTICAL ANALYSISMAM ANUM REHMAN

The purpose of this presentation is to get you through the basic concepts of titration and explain all the details of acid-base titration so that you won't have to open google again whenever you are standing in the lab.

INDEX

ALL THAT YOU NEED TO KNOW

Meet The Team

Description

Process

Titration

Calculations

Terminologies

Conditions

Indicators

Types

Types of acid-base titration

Acid-Base Titration

Applications

Apparatus

meet the team

Komal Iftikhar Roll No 57

Hajrah Iftikhar Roll no 67

Ayesha Fatima Roll No 103

Zainab Ali Roll No 51

Nida Iftikhar Roll No 55

Aiman Arif Roll No 97

DESCRIPTION

• The word titration descended from the French word titre in 1828 the French chemist Joseph Gay Lussas first used the term titre "to determine the concentration of a substance in a given sample."

• It's a type of quantitative analysis called as titrimetry.

TITRATION

The term "titrimetric analysis" refers to quantitative chemical analysis carried out by determining the volume of a solution of accurately known concentration which is required to react quantitatively with a measured volume of a solution of the substance to be determined

IMPORTANT TERMINOLOGIES

• Titrant (Standard Solution)
• Titrant (Analyte)
• Equivalence point
• Indicator
• End Point
• Titration Error
• Titration curve
• Concentration
• Molarity
• Normality
• Molality

IMPORTANT TERMINOLOGIES

Terms You Should Know

TITRANT

It is a solution with a known concentration, which is used as a standard solution in titration. This solution is taken in the burette.

BURETTE

The only essential piece of equipment for an acid-base titration isa means for delivering the titrant to the solution containing the analyte. The most common method for delivering the titrant is a buret. A buret is a long, narrow tube with graduated markings and a stopcock for dispensing the titrant.

IMPORTANT TERMINOLOGIES

Terms You Should Know

TITRAND (ANALYTE)

The substance being titrated is known as Titrand. It's also known as Test Solution.

EQUIVALENCE POINT

(Theoretical Or Stoichiometric End Point)

The point in a titration where stoichiometrically equivalent amounts of analyte and titrant react.

IMPORTANT TERMINOLOGIES

Terms You Should Know

END POINT

The point in a titration where we stop adding titrant.

INDICATOR

The completion of the titration is detected by some physical change,produced by the standard solution itself or more usually, by the addition of an auxiliary reagent, known as an indicator; alternatively some other physical measurements may be used.

IMPORTANT TERMINOLOGIES

Terms You Should Know

TITRATION ERROR

In the ideal titration, the visible endpoint will coincide with the stoichiometric or theoretical endpoint. In practice, however, a very small difference usually occurs, this represents the titration error. The indicator and the experimental conditions should be selected so the difference between the visible endpoint and the theoretical end point is as small as possible.

IMPORTANT TERMINOLOGIES

Terms You Should Know

TITRATION CURVE

• A titration curve provides us with a visual picture of

how a property such as pH, changes as we add titrant.

• We can measure this titration curve experimentally by

suspending a pH electrode in the solution containing the analyte, monitoring the pH as titrant is added.

To find the end point we monitor some property of the titration reaction that has a well-defined value at the equivalence point. For example, the equivalence point for a titration of HCI with NaOH occurs at a pH of 7.0. We can find the endpoint therefore, by monitoring the pH with a pH electrode or by adding an indicator that changes color at a pH of 7.0.

IMPORTANT TERMINOLOGIES

Terms You Should Know

CONCENTRATION

The concentration of a substance is the quantity of solute present in a given quantity of solution.

MOLARITY

Moles (gram molecular weights) of solute in 1 liter of solution.

IMPORTANT TERMINOLOGIES

Terms You Should Know

NORMALITY

The concentration of a substance is the quantity of solute present in a given quantity of solution.Concentrations are usually expressed in terms of Molarity, Normality and Molality.

MOLALITY

Moles of solute in 1000 g of solvent.

TYPES OF TITRATION

Acid-Base Titration

Non-aqueous Titration

Redox Titration

Complex- ometric Titration

Argenntometric Titration

ACID-BASE TITRATION (NEUTRALIZATION)

It is a quantitative analysis method to deterimne acids or bases' concentration by precisely neutralizing them with a standard solution of either acid or base of known concentration is called as acid base titration

ALKALIMETRY

ACIDIMETRY

the strength of a base can be found with the help of a standard solution of an acid which is called as Alkalimetry

the strength of an acid can be determined by using a standard solution of base this process is called acidimetry

PRINCIPLE

Analyte is chemically reacted with a standard solution of a reagent of precisely known concentration or with a concentration that can be precisely determined. The amount of a standard solution required to completely react with the entire sample is used to estimate the purity of the sample.

APPARATUS

• Burette stand
• Burette
• Conical flask
• Droper

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PROCEDURE

step 03

step 02

step 01

Record the initial burette reading

Filled the burette with the standarized solution of acid or base

Fit a clean butette vertically in a burette stand

PROCEDURE

step 06

step 05

step 04

Run the burette solution dropwise in the flask and constantly shake the flask

Add few drops of phenolphthalein(indicator)in the conical flask.

Slowly add the standarized solution of acid or base in the conical flask

PROCEDURE

step 08

step 07

When the color changes this is called as end point

Adding the solution till the color changes to light pink from colorless

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CALCULATIONS

Calculate the concentration of 50 ml HCl solution taken in a flask if 25 ml of 1M NaOH is used to reach the endpoint?

THINK TANK

"Can Any Reaction Undergo Tritimetry Or Are There Some Sort of Conditions That Must Be Fulfilled??"

There must be a simple reaction which can be expressed by a chemical equation; the substance to be determined should react completely with the reagent in stoichiometric or equivalent proportions.

The reaction should be relatively fast. (Most ionic reactions satisfy this condition.) In some cases the addition of a catalyst may be necessary to increase the speed of a reaction.

There must be an alteration in some physical or chemical property of the solution at the equivalence point.

An indicator should be available which, by a change in physical properties (colour or formation of a precipitate), should sharply define the end point of the reaction.

INDICATORS

• A large number of substances, called neutralisation or acid-base indicators, change colour according to the hydrogen-ion concentration of the solution.
• The chief characteristic of these indicators is that the change from a predominantly 'acid' colour to a predominantly 'alkaline' colour is not sudden and abrupt but takes place within a small interval of pH termed the colour-change interval of the indicator.

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Color Change And pH Range of Certain Indicators

MECHANISM Theories

OSTWALD THEORY

ACID-BASE THEORY

Indicators are either present in benzenoid from or quinonoid form in the indicator

Every indicator is either a week base or a week acid.

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Universal Indicators

• By mixing suitable indicators together changes in colour may be obtained over a considerable portion of the pH range.
• Such mixtures are usually called 'universal indicators'.
• They are not suitable for quantitative titrations but maybe employed for the determination of the approximate pH of a solution by the colorimetric method.

pH PAPER

• The level of pH is measured with pH paper

and will determine if a solution is acidic, alkaline, or neutral.

• This is done by dipping the pH paper into a solution and observing the change in color of the paper.

CITATION

A simple experiment for you to understand it more extensively

STRONG BASE

The base which dissociate completely are strong base

The base which dissociate partially are weak base

WEAK BASE

The acid which dissociate completely are strong acid

STRONG ACID

The acid which dissociate partially are weak acid

WEEK ACID

TYPES OF ACID-BASE TITRATION

Weak Acid With Weak Base

Weak Base With Strong Acid

Strong Acid With Strong Base

Weak Acid With Strong Base

TYPES OF ACID-BASE TITRATION

Weak Base With Strong Acid

Weak Acid With Weak Base

• The weak acid is partially dissociated and is neutralized with the NH3 which is a weak base.

• The weak acid is taken into the conical flask and then the appropriate indicator is added.

• Then it is titrated with the weak base until the colour change appears

• The weak base is taken into the conical flask and a small quantity of the indicator is added.
• Then the resulting solution is titrated with the strong acid.
• The plot between the pH and the volume of the titrant shows the initial decrease in the pH and at the endpoint it shows the rapid pH drop and remains constant.

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TYPES OF ACID-BASE TITRATION

Weak Acid With Strong Base

Strong Acid With Strong Base

• The weak acid is partially dissociated into H+ ions that are neutralized by the strong base which produces OH- ions.
• The weak acid is taken into the conical flask and the appropriate indicator is added and then titrated with the strong base until the color change persists.

• The strong acid is completely dissolved in the water and it produces the H+ ions which are neutralized by the OH- ions present in the strong base solution.
• At the equivalence point, the H+ ions are completely neutralized by the OH- ions. Then the plot is drawn between the pH and volume of the titrant.

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REAL-WORLD APPLICATIONS

Acid base titration is commonly used in pharmaceutical applications for quality control and analysis. It helps to determine the concentration of active pharmaceutical ingredients, ascess the purity of substances and ensure the proper formulation of drugs

APPLICATIONS

ASPIRIN DETERMINATION

Amino acid determination

Ph CONTROL

• Titration is useful in maintaining the pH. of pharmaceutical solutions within specified ranges.
• This is critical for the stability and effectiveness of many drugs.

• Sample is added to the 25ml distilled water and small increments of HCI is added to maintain the pH to 1.5.
• Then it is titrated with standard NaOH solution using phenolphthalein as indicator.
• The procedure is continued until the pH is reached to 12.

• Sample is dissolved in the ethanol and then 2 to 3 drops of phenolphthalein is added as an indicator.
• Then the resulting solution is titrated with standard NAOH solution until pink color is obtained.

APPLICATIONS

API PURITY

API Purity

Nicotinic Acid Determination

• Assessing the purity of API is crucial in pharmaceutical manufacturing.
• Acid base titration can be used to determine impurity levels by reacting the sample with a standardized solution of an acid or base and measuring the volume needed for neutralization.

• Assessing the purity of API is crucial in

pharmaceutical manufacturing.

• Aid base titration can be used to

determine impurity levels by reacting to the sample with a standardized solution of an acid or base and measuring the volume needed for neutralization.

• Nicotinic acid is analysed mainly by the titrimetric method based upon the acid base principle.
• Nicotinic acid is titrated with standard alkali like NaOH using phenolphthalein as indicator.

APPLICATIONS

Oil and fat analysis

cheese production

FOOD INDUSTRY

• Titration is frequently used in the food industry to keep the acid, base, and salt content in the food products under supervision.
• For example, Acetic acid in vinegar, Ketchup, etc.
• It is also used to determine the acidity of food products. such as fruit juices like orange juice, lemon juice, and dairy products.

• In this case, titration is important when measuring

the pH and acidity of the initial milk being used to make cheese.

• At the end of cheese cheese-making process acidity of the cheese is also measured.

• Titration methods are used to determine the acidity value of oils and fats.
• This is important for assessing the quality of cooking oil and ensuring it meets specified standards.

AUTOMATIVE TITRATION

References

• Pharmaceutical Analysis (A textbook for pharmacy
• students and pharmaceutical chemists) by
• David G. Watson
• Quantitative analysis by V. Alexeyev
• Quantitative Chemical Analysis by Daniel C. Haris
• Pharmaceutical analysis by P. D. Chaithanya Sudha
• Titration by Tanvi Lavanya joshi
• Vogel's Textbook of Quantitaive Chemical Analysis

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