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
Marco Diogo Richter Gomes da Silva
Hours
Weekly - 2
Total - 36
Teaching language
Português
Prerequisites
n.e.
Bibliography
1. 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.
2. Destruction of Hazardous Chemicals in the Laboratory. George Lunn, Eric B. Sansone, Wiley-Interscience; 2nd ed, 1994.
3. Purification of Laboratory Chemicals. D.D. Perrin, W.L. Armarego, Pergamon Press; 3rd ed, 1993.
Endereços electrónicos
4. Online Safety Library: Laboratory and Chemical Safety
http://ehs.okstate.edu/
5. 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 assessment is continuous according to the FCT-NOVA knowledge assessment regulation and includes the following elements affected by the indicated weighting:
a) Practical Component (50%): Groups of 2. Each student must attend all the practicas sessions. Individual laboratory notebook.
i) Student performance in the laboratory throughout the semester''''s practical classes (30%),
ii) Individual laboratory notebook, preparation and records (20%).
b) Theoretical-practical component - Final test (50%),
c) Each student must attend all practical classes as indicated in point a).
d) The assessment elements in paragraph a) are mandatory to obtain attendance, whose grade must be equal to or greater than 9.46.
e) The weighted average of the classification of each of the two evaluation elements - Practical Component + final test - must be ≥ 9.46 values for approval in the UC. The final test has no minimum grade but the student MUST attend the test. If you miss the final test, the student DOES NOT APPROVE the UC in continuous assessment, being admitted to the exam in accordance with paragraph f).
f) If the student does not pass continuous assessment and attends the UC in accordance with sub-paragraphs a) and d), he is admitted to the final exam in which the Final Exam Grade will correspond to the final grade in the CU.
g) For students who obtain frequency but do not pass the UC, they maintain the classification of frequency for the following academic year and may, if desired, take the UC in the following academic year by continuous assessment.
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.
9th session: Extraction, isolation and characterization of pigments