Analytical Chemistry Lecture 2

Analytical Chemistry

• Analytical chemistry involves the separation, identification, and quantification of matter.
• It involves the use of classical methods along with modern methods involving the use of scientific instruments.

Branches of Chemistry

• Organic Chemistry: the study of carbon and its compounds, including the study of life and reactions in living organisms.
• Inorganic Chemistry: the study of compounds not covered by organic chemistry, including inorganic compounds, metals, and minerals.
• Analytical Chemistry: the study of the chemistry of matter and the development of tools to measure properties of matter.
• Physical Chemistry: the branch of chemistry that applies physics to the study of chemistry.
• Biochemistry: the study of chemical processes that occur inside living organisms.

Analytical Chemistry Consists Of

• Qualitative analysis: deals with the identification of elements, ions, or compounds present in a sample.
• Quantitative analysis: deals with the determination of the amount of one or more constituents present in a sample.
• Three branches of quantitative analysis:
  • Volumetric analysis (Titrimetric analysis): involves the reaction of the analyte with a measured volume of reagent of known concentration.
  • Gravimetric analysis: involves the selective separation of the analyte by precipitation, followed by the measurement of mass.
  • Instrumental analysis: involves the measurement of a physical property of the sample, such as electrical property or absorption of electromagnetic radiation.

Importance of Analytical Chemistry

• Analytical chemistry plays an important role in many sciences, including biology, medicine, and industry.
• It is used to study living materials, food processing, and diagnosis of diseases.
• It is essential in industrial production to ensure the quality of raw materials, products, and processes.

Applications of Analytical Chemistry

• Determining the shelf life of drugs.
• Testing soil for the presence of minerals and nutrients necessary for plant growth.
• Classifying human blood samples.

Solutions

• A homogenous mixture of two or more substances, where one is the solute and the other is the solvent.
• Classification of solutions:
  • Based on the nature of molecules: true solution, suspended solution, and colloidal solution.
  • Based on solute concentration: saturated solution, unsaturated solution, and super saturated solution.
• Units of weight and concentration:
  • Physical units: gram, milligram, kilogram.
  • Chemical units: atomic weight, molecular weight, formula weight, ionic weight, equivalent weight.

Molecular Weight

• Defined as the mass of a given substance divided by the amount of substance, expressed in grams per mole (g/mol).
• Calculated from the atomic masses of each nuclide present in the molecule.
• Example calculations: Fe(OH)3.12H2O, hexane (C6H14), and other molecules.

Classification of Solutions Based on Solute Particle Size

• True solution: a homogeneous mixture of two or more substances in which the substance has a particle size less than 1 nm dissolved in the solvent.
• Suspension solution: a heterogeneous mixture which settles on standing and its components can be separated by filtration.
• Colloidal solution: a homogeneous mixture which does not settle nor are its components filterable, with solute particles visible with an electron microscope.