Analytical Chemistry Overview

Course Aims

• Students will be able to explain theoretical bases and applications of acid-base, preciptimetric, complexometric, and gravimetric reactions.

Assessment

• 10% Midterm exam
• 5% Activity
• 25% Practical exams
• 10% Oral exams
• 50% Final written exam

Assessment Schedule

• Midterm exam in week 7
• Activity in week 11
• Practical exams in week 13
• Final written exam in week 15
• Oral exams in week 15

What is Chemistry?

• Everything is a chemical
• Examples: table salt (sodium chloride, NaCl), table sugar (sucrose, C12H22O11C_{12}H_{22}O_{11}C12​H22​O11​), clothes (wool, cotton, polyester), body (lipids, proteins, carbohydrates, DNA/RNA)

Main Branches of Chemistry

• Organic Chemistry
• Inorganic Chemistry
• Physical Chemistry
• Biochemistry
• Analytical Chemistry

What is Analytical Chemistry?

• Branch of chemistry focused on analyzing different substances
• Involves separation, identification, and quantification

Types of Questions in Analytical Chemistry

• Qualitative analysis: What is in the sample? (identity)
• Quantitative analysis: How much is in the sample? (amount)

Importance of Analytical Chemistry

• Medical diagnosis (e.g., serum cholesterol, urine ketones, disease markers, blood glucose levels)
• Forensic survey (e.g., DNA fingerprinting, poison analysis in blood samples)
• Soil testing (e.g., mineral and nutrient analysis, pesticide residues)
• Food industry (e.g., food contaminant analysis, preservative concentration)
• Pharmaceutical industry (e.g., drug shelf life determination, adulterant detection, drug impurity analysis, active constituent concentration)

Analytical Chemistry as the “Central Science”

• Central to scientific fields such as:
  • Medicine
  • Toxicology
  • Pharmacology
  • Biochemistry
  • Biology
  • Botany
  • Agriculture
  • Ecology
  • Neurology
  • Physiology
  • Psychology
  • Paleontology
  • Geology
  • Physics
  • Astronomy
  • Meteorology
  • Electronics
  • Archaeology
  • Metallurgy
  • Engineering

Analytical Chemistry Branches

• Qualitative analysis
• Quantitative analysis
  • Classical "Wet" analysis
    • Gravimetric analysis
    • Volumetric analysis
  • Instrumental analysis
    • Optical methods
    • Separation methods
    • Electro-analytical methods

Classical Methods (Wet Analysis)

• Analysis done generally in the liquid phase without advanced instrumentation
• Effective and widely used
• Includes volumetric analysis and gravimetric analysis

Instrumental Analysis

• Uses specific apparatus for measurements with computer processing and data analysis
• Depends on analyte's physico-chemical, optical, and electrical properties
• Examples: spectrophotometric, potentiometric, and conductometric methods

Volumetric Analysis (Titration)

• Measures the volume of a solution containing sufficient reagent to react completely with the analyte
• Used to determine the unknown concentration of a known reactant
• Common technique is titration

Gravimetric Analysis

• Measures the mass of the final product of a reaction after isolation in pure and stable form with a definite chemical structure

Classifications of Volumetric Analysis by Reaction Type

• Titration
  • Acid-base Titration
  • Redox Titration
  • Precipitation Titration
  • Complexometric Titration

Acid-Base Titration

• Uses a neutralization reaction between an acid and a base
• Involves a pH change, monitored using an indicator
• Example: Titration of a strong acid with a strong base
• Key factors: equivalence point, end point, indicator selection

Redox Titration

• Uses a reaction involving electron transfer (oxidation and reduction)
• Requires a suitable redox indicator
• Example: Titration of potassium permanganate with iron (II) sulfate
• Key factors: standard oxidizing or reducing agent, stoichiometry

Precipitation Titration

• Forms a precipitate in the reaction
• Utilizes a precipitation reaction between two reactants
• Example: Titration of silver nitrate with sodium chloride
• Key factors: solubility product, common-ion effect

Complexometric Titration

• Forms a soluble complex between the analyte and a reagent
• Involves a complex formation reaction between metal ions and a complexing agent
• Example: Titration of calcium ions with EDTA
• Key factors: complex formation constant, pH control

Gravimetric Analysis

• Based on weighing the final product of a reaction after isolation in pure and stable form with a definite chemical structure
• Includes precipitation gravimetry, volatilization gravimetry, and electrogravimetry
• Example: Determination of chloride content by precipitation as silver chloride - Key factors: solubility of the precipitate, purity of the precipitate, stoichiometry of the reaction

Key Terms in Analytical Chemistry

• Analyte: The substance being analyzed
• Reagent: A substance used to react with the analyte
• Standard solution: A solution of known concentration
• Indicator: A substance that changes color to indicate the endpoint of the reaction
• Equivalence point: The point at which the analyte and reagent have reacted in stoichiometric amounts
• End point: The point at which the indicator changes color

General Steps in Volumetric (Titration) Analysis

• Preparation of standard solution
• Titration procedure
• Calculation of results

General Steps in Gravimetric Analysis

• Precipitation of the analyte
• Filtration, washing, and drying
• Weighing the precipitate
• Calculation of results

This quiz covers the fundamentals of analytical chemistry, focusing on key theoretical bases and application techniques including acid-base reactions, gravimetric, and complexometric methods. It also highlights the main branches of chemistry and the nature of substances we encounter in everyday life.