Laboratory Techniques

Objectives

Preparing students for the efficient conduct of the main experimental techniques used in chemistry: preparation of solutions, titration, determination of physical constants, recrystallization, sublimation, distillation, liquid-liquid extraction, solid-liquid extraction, filtration and chromatography.

Acquisition of experimental skills to perform the operations effectively, and safely as well as the acquisition of the knowledge necessary for a correct interpretation of results. It is intended that students acquire the fundamentals of general organization of the chemistry lab, safety rules, good laboratory practices, organized and accurate record of work done in the lab notebook and prepare reports.

 

 

General characterization

Code

10824

Credits

3.0

Responsible teacher

Luísa Maria da Silva Pinto Ferreira

Hours

Weekly - 2

Total - 30

Teaching language

Português

Prerequisites

NA

Bibliography

Introduction to Organic Laboratory Techniques, A Small Scale Approach. R.G. Engel, G.S. Kriz, G.M. Lampman and D.L. Pavia, 3rd ed. Brooks/Cole 2011.

Online Safety Library: Laboratory and Chemical Safety http://ehs.okstate.edu/

ChemKeys http://www.chemkeys.com/bra/index.htm

Teaching method

Face-to-face teaching with laboratory and problem-solving sessions. Laboratory sessions are tutored classes, guided by a teacher, of compulsory attendance to apply the most common techniques in chemistry and biochemistry laboratories. problem-solving sessions take place after lab sessions in order to demand student analys of the experimental execution of presented techniques.

Evaluation method

The requirements for achievement are as follows:
1) Continuous assessment:
- Compulsory attendance of all laboratory sessions.
- Final classification resulting from the application of the following parameters: 20% laboratory notebook, 30% laboratory performance, 10% laboratory session report, 10% written quiz, 30% laboratory practice test.
2) Final exam: The practical test can be replaced by the written exam at exam time.
Approval with an overall grade of 9.5 or higher and 9.5 on the practical test or exam.

Subject matter

Organization of a chemical laboratory. Safety and good laboratory practices. Environmental protection and waste management in the laboratory. Methodology of work in the laboratory: preparation work, experimental implementation, specification of laboratory preparation and submission of reports.

General laboratory techniques: measuring, mixing, dissolving, heating / cooling, stirring. Mounts for laboratory work. Preparation of solutions. Dilutions. Titration. Measurement of physical constants. Procedures for purification of solids, recrystallization and sublimation. Process for purifying liquids, distillation. Extraction processes: liq - liq and sol - liq. Filtration. Chromatography: column chromatography and thin layer chromatography. Analytical and preparative chromatography. Determination of contents in solution.

Practical sessions

1st session: Presentation of the Laboratory. Identification of general laboratory equipment. Safety rules in the chemistry lab. Weighing, preparing solutions, measuring volume and solutions preparation.

2nd session: Determination of physical constants: melting point, refractive index and density

3rd session: Preparation of acid and base solutions at different concentrations. Acid-base titration.

4th session: Purification of solids: recrystallization and sublimation.

5th session: Purification of liquids: fractional distillation. Demontration of distillation under reduced pressure and steam distillation.

6th session: Liquid-liquid extraction. Drying agents. Gravity filtration. Evaporation to dryness. Solid-liquid extraction. Notion of extract.

7th session: Column chromatography and thin layer chromatography.

8th session: Content determination. Preparation of solutions / dilution calculations / calibration line.