Tools of Analytical Chemistry.pdf

LABORATORY INTRODUCTI ON TOPIC OUTLINE:  Laboratory Laboratory Apparatus Introduction Laboratory Rules  GENERAL INSTRUCTIONS RULES AND PROCEDURES FOR A SAF...

LABORATORY INTRODUCTI ON TOPIC OUTLINE:  Laboratory Laboratory Apparatus Introduction Laboratory Rules  GENERAL INSTRUCTIONS RULES AND PROCEDURES FOR A SAFE LABORATORY EXPERIMENT THE APPARATUS The common laboratory apparatus  used in Chemistry is found in the Instrumentation Room. It would be beneficial for the student to be acquainted with the names and appearance of such equipment at the very beginning of their laboratory work. THE APPARATUS The instructor will issue many of these apparatuses to the students for the latter's use during the semester. Since the students will be held responsible for the equipment loaned  to them, they should carefully check all the apparatus received. THE APPARATUS They should have a duplicate copy of all apparatus or equipment received and signed for by them. Any apparatus broken or lost has to be replaced or paid for by the student. If the apparatus were issued to a group of students, the receipt has to be signed by all the group members. The group members will share equally the cost of replacement or payment for any breakage or loss made during the semester, no matter who lost or broke the equipment.  expected results. 01. 02. RULES IN CONDUCTIN RULES IN G THE Understand the CONDUCTIN EXPERIMENT objectives of the G THE experiment. S EXPERIMENT S Study the theory or theories involved using textbooks and other references as a guide. Formulate all possible reactions (main and side reactions) that may take place during the experiment. Visualize the  do not get excited, and do not rush. 03. 04. 05. 06. RULES IN CONDUCTIN G THE Develop an analytical Plan the work ahead of time. List all the mind and powers of materials and apparatus needed so that when you begin your work in the EXPERIMENT mechanically. reasoning. Do not work laboratory, you bring around only your list while securing the materials in the S instrumentation room. Know the purpose of each substance used, each Follow the directions accurately in apparatus's functions, and the your laboratory guide to obtain the reasons for each step in the best results. Always keep busy, but experiment. Write equations for the reactions involved. explanation of your fellow students. 07. 08. RULES IN CONDUCTIN RULES IN G THE When some directions or instructions are vague, do not EXPERIMENT instructor. hesitate to consult the laboratory 09. S Make conclusions only after doing a careful analysis of observations. Hasty conclusions are always harmful, and many times are If you fail to get the dangerous. expected results, try to analyze the cause, and confer with your instructor. Do not depend on the  to erroneous results. CONDUCTIN 11. 12. G THE EXPERIMENT RULES IN S CONDUCTIN G THE Keep tables and shelves clean and dry EXPERIMENT before leaving the 10. S laboratory. The laboratory equipment, especially the glassware and porcelain, should be Makes the canal leading to the clean, shiny, and ever ready for use. The sink free from insoluble dirt such contamination of dirt into the working as filter paper, glass tubes, and materials introduces impurities and leads match sticks so as not to clog the sink. 13. 14. Wipe any reagent spilled on the balance pans immediately. RULES IN CONDUCTIN Throw acid waste G THE into the "acid jars" and solid materials into the garbage bin to protect RULES IN EXPERIMENT the sink. S CONDUCTIN G THE EXPERIMENT S S In heating reacting 17. 18. substance in the test tube make 15. 16. sure that the test tube mouth is not pointing towards your classmate. Avoid making Do not shake glass rod or unnecessary noise; instead, talk in RULES IN test tubes with acid and strong base towards your subdued voices while working in the CONDUCTIN classmate. laboratory. G THE EXPERIMENT  S Be considerate of the right of your neighbors to a safe and Read the label of the reagent bottle and do not assume its content. 19. 20 enjoyable laboratory period. RULES IN RULES IN Do not bother your classmates by CONDUCTIN CONDUCTIN borrowing soap or matches or by G THE G THE incessantly asking EXPERIMENT questions. EXPERIMENT S  Be cooperative, the time and have an owner helpful, and unselfish to one attitude to have a conducive place 21. 22. another. to work which inspires you to think new ideas that will lead to a more significant discoveries. Keep the laboratory room tidy all THE LABORATORY SAFETY MEASURES To minimize and prevent the danger of accidents arising from explosions, breaking of glass apparatus, and the likes, the following suggestions are offered. SAFETY MEASURES ON HOW TO HANDLE LABORATORY APPARATUS Students should not work in the laboratory without an instructor in charge. Unless a special permit has been secured, no unassigned experiments must be performed When heating the contents of a test tube, the tube should be held in a slanting direction upward and not pointed towards anybody. When directed to "note the odor" of the issuing vapor, do not place the mouth of the test tube towards your nose; simply waft the vapors with the hand towards the nose. If the odor is not yet perceptible, then bring the receptacle nearer to the nose. Do not heat a test tube or flask when the stopper is tightly closed. SAFETY MEASURES ON HOW TO HANDLE LABORATORY APPARATUS Experiments producing irritating or poisonous vapors should be performed under the HOOD. Handle concentrated acids with care. Avoid the contact of the acids with the skin as these substances cause painful burns. Acids are poured into water and never the water into the acids. The reverse will cause the mixture to sputter all over. Potassium cyanide, arsenic trioxide, mercuric chloride, etc. are very poisonous. Do not taste it. Whenever directed to taste a substance, just place with the finger a minimal amount of the substance at the tip of your tongue and then rinse the mouth immediately with water. SPIT IT OUT. SAFETY MEASURES ON HOW TO HANDLE LABORATORY APPARATUS In cutting or inserting glass tubing, hold the glass tubing with a towel Label all containers properly. Return all bottles, reagents, etc. to their proper places. Have self-control, presence of mind, and poise when accidents happen. SAFETY MEASURES ON HOW TO HANDLE LABORATORY APPARATUS Take every precaution to prevent fires. Flames should never be brought near open vessel containing alcohol, ether, petroleum, benzene, etc. Live match sticks should not be thrown into the garbage can. Consult the laboratory instructor for the proper disposal of phosphorous wastes or any unused phosphorous. When a small fire breaks, turn off the gas quickly, then smother the flame either with a wet towel or an asbestos pad. Some students practice keeping a wet rag in the sink while the experiments are going on, "just in case." If these are not effective, use the fire extinguisher. In case the fire originated from phosphorus or sodium, put it out by throwing sand on it. In case of a big fire, call the fire department. Report all accidents to the instructor at once. Even minor cuts and burns should be treated promptly.  concentrated acids, etc. Do not handle solid KOH and NaOH. Be sure you are getting the right materials. A wrong mixture of materials may cause accidents such as explosions, burns, SAFETY etc. in the laboratory. Therefore, reading the label is essential when picking the container; removing the MEASURES ON stopper, and returning the bottle to its place. HOW TO HANDLE CHEMICALS 01. Be careful in handling such chemicals 02. Use only pure substances as reagents to get accurate and as bromine, phenol, phosphorus, reliable results. phosphorus trichloride, acetyl chloride, SAFETY MEASURES ON HOW TO HANDLE CHEMICALS 03. 04. Any extra number of reagents obtained from stock bottles should not be returned to the container to avoid contaminating the rest of the bottle's contents. Therefore, you should get only enough of the amount needed to avoid waste. Follow the proper laboratory methods. Make it a point to use a clean and dry apparatus. It is important to clean and invert (to drain) all the apparatus before leaving the laboratory so that it is dry before the next laboratory period. Connect your apparatus with care and follow the 05. specifications in the laboratory guide. Fit stoppers tightly. Glass tubing should have rounded bends, and the ends should be fire-polished. Glass tubes joined by rubber should touch end-to-end to avoid as much as possible contact SAFETY between the rubber tube and the chemicals. Paper, cloth, paraffin, etc. should not be used to MEASURES ON "patch" loose connections. By using the right size of cork-borer, glass tubing can be made to fit the holes tightly. The apparatus must be inspected and checked by the HOW TO HANDLE laboratory instructor before the actual experiment CHEMICALS LABORATORY ACCIDENTS AND FIRST AID 02. 03. 01.  Eye accidents: Skin Accidents a. Acid in the eyes Wash the eye a. Acid on the skin Organic substances on repeatedly with large amount of water and Wash immediately with plenty of then with bicarbonate solution. water, then with saturated NaHCO3 the skin: b. Caustic alkali in the eye Wash the eye solution, then with water again. In a Wash freely with rubbing with large amount of water and then 1% more serious case, apply a boric acid solution. alcohol, then with soap disinfectant after this procedure and c. Bromine in the eye Wash with large and warm water. then apply acriflavine jelly. amount of water and then with 1% NaHCO, solution. LABORATORY ACCIDENTS AND FIRST AID 03. 04. 03. acid then with water again. C. Burns For a serious case, apply a c.1 For burns cause by dry heat in b. Alkaline on the skin Wash which the skin is not broken apply disinfectant after this immediately with plenty of tannic acid jelly. procedure and then apply water, then with 1% acetic c.2 For burns in which the skin is acriflavine jelly.  reddened and blistered, apply crystal proof blanket around the ignited a. Burning clothing Prevent violet jelly without delay and then clothes until the fire is person from running and fanning consult the doctor immediately. extinguished the flames. Make the victim lie Fires down on the floor and wrap a fire LABORATORY ACCIDENTS AND FIRST AID 03. 04. 04. which the skin is not broken apply person from running and fanning tannic acid jelly. the flames. Make the victim lie b. Burning reagents Turn off c.2 For burns in which the skin is down on the floor and wrap a fire all the gas burners. Use a fire reddened and blistered, apply crystal proof blanket around the ignited extinguisher. violet jelly without delay and then clothes until the fire is consult the doctor immediately. C. Burns extinguished Fires c.1 For burns cause by dry heat in a. Burning clothing Prevent LABORATORY ACCIDENTS  AND FIRST AID 03. 04. 04. For larger fires, dry sand may be used if a milk of magnesia. Milk can be also be fire extinguisher is not available given but not any emetic. b. Burning reagents Turn off all the 5. Poisons b. Alkali- Drink plenty of water, followed gas burners. Use a fire extinguisher. a. Acid - If an acid is swallowed, drink by vinegar, lemon orange juice. Milk c. For Burning liquid in a vessel Cover the plenty of water, followed by lime water ormay also be given by not any emetic. mouth of the vessel with clean damp cloth. SELECTING AND  HANDLING CHEMICALS RULES IN HANDLING REAGENTS AND SOLUTION AVOID contamination! Small bottles if possible Don’t leave the top open, don’t put the stopper in any surface er Use your pinky finger when opening the bottle  No return policy unless stated, shake the bottle for incrustation. (If ineffective clean porcelain spoon can be used) Clean Proper waste disposal CLEANING AND MARKING LABORATORY WARE Equipment/s that has small etched areas for marking ⚬ Flask ⚬ Beaker ⚬ Crucibles Purpose on marking? Material used for marking: ⚬ Pencil ⚬ Special marking inks  ⚬ Saturated Iron Chloride (FeCl3) CLEANING AND MARKING LABORATORY WARE Clean before and after use Steps in washing ⚬ Hot liquid detergent ⚬ Tap water ⚬ Deionized water ⚬ Note: If greasy try using organic solvents Never dry before use EVAPORATING LIQUIDS  Bumping ⚬ violent boiling that tends to spatter solution Wet-ashing ⚬ removal/ oxidation of organic compounds using heat and strong acid MEASURING MASS Analytical Balance ⚬ use to obtain accurate measurement ⚬ maximum capacity of 1g to few kg with a precision of at least  1 part in 105 of maximum capacity Triple Beam Balance simple, durable, and low-cost PRECAUTIONS IN USING ANALYTICAL BALANCE Center the load Protect from corrosion Special precautions Adjust Clean (Camel Hair Brush)  Do not weigh hot objects Use tongs/ finger pads to avoid moisture BEAKER ERLENMEYER FLASK VOLUMETRIC FLASK GRADUATED CYLINDER TEST TUBE BEAKER TONGS TEST TUBE HOLDER  TEST TUBE BRUSH SPATULAS Spatulas are used to dispense solid chemicals from their containers. SCOOPULA THERMOMETER MEDICINE DROPPER TEST TUBE RACK GLASS STIRRING ROD BUNSEN BURNER RETORT STAND C-CLAMP IRON RING Iron rings connect to a ring stand and provide a stable, elevated  platform for the reaction. BURETTE CRUCIBLE CLAY TRIANGLE The clay triangle is used as a support for porcelain crucibles when being heated over a Bunsen burner. CRUCIBLE TONGS  For handling hot crucibles; also used to pick up other hot objects. FUNNEL FILTER PAPER MORTAR & PESTLE EVAPORATING DISH PETRI DISH WATCH GLASS HOT PLATE PIPETTE SPOT PLATES Spot plates are used when we want to perform many small scale reactions at one time. RUBBER STOPPER Rubber stoppers are used to close containers to avoid spillage or contamination. FORCEPS Forceps (or tweezers) are used to pick up small objects. WASH BOTTLE A wash bottle has a spout that delivers a wash solution to a specific area. THANK YOU VERY MUCH!