Laboratory Techniques
Objectives
Acquisition of fundamental notions of:
- General organization of the chemistry laboratory
- Security rules
- Good laboratory practices
- Accurate and organized recording of the work carried out in the laboratory notebook
- Preparation of reports.
Preparation for the efficient performance of the main experimental techniques used in chemistry:
- Preparation of solutions
- Titration
- Determination of physical constants
- Recrystallization and filtration
- Sublimation
- Distillation
- Liquid-liquid and solid-liquid extraction
- Chromatography.
Acquisition of experimental skills to carry out the aforementioned operations effectively and safely, as well as the acquisition of the knowledge necessary for a correct interpretation of the results.
General characterization
Code
10824
Credits
3.0
Responsible teacher
Luísa Maria da Silva Pinto Ferreira, Marco Diogo Richter Gomes da Silva
Hours
Weekly - 2
Total - 33
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.
Internet addresses
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 regulations and includes the following elements affected by the indicated weighting:
a) Practical Component (50%): Groups of 2 members and all students must register all work, including preparation of the work and recording of the work carried out. Individual laboratory notebook. This evaluation takes place during the semester
i) student preparation and performance in the laboratory throughout the semester''s practical classes (30%),
ii) individual laboratory notebook (20%).
b) Theoretical-practical component - Final test (50%),
c) Each student must attend all practical classes.
d) The assessment elements in paragraph a) are mandatory to obtain frequency, the score of which must be equal to or greater than 9.5.
e) The weighted average of the classification of each of the two assessment elements – Practical Component + final test – must be ≥ 9.5 values to pass the curricuilar unit (CU). The final test does not have a minimum grade but the student MUST attend the test. If the student fails to take the final test, the student will NOT APPROVE the CU and will be admitted to the exam in accordance with paragraph f).
f) If the student does not pass the continuous assessment and attends the UC in accordance with paragraphs a) and d), he or she is admitted to the final exam in which the Final Exam Grade corresponds to the final grade in the CU.
g) For students who obtain frequency but do not pass the CU, they maintain their attendance classification for the following academic year and may, if they wish, take the CU in the following academic year through 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