PHA612LAB - CHAPTER 1 AND 2.pdf

[1BPH 2026] CHAPTER 1 – LAB SAFETY AND APPARATUS Maintain cleanliness in the laboratory especially in your OUTLINE...

[1BPH 2026] CHAPTER 1 – LAB SAFETY AND APPARATUS Maintain cleanliness in the laboratory especially in your OUTLINE working area. I Chemical Safety and Laboratory Rules o Plastics, pieces of paper, and solid substances should A Laboratory Apparel be thrown in the garbage can. B Safety Equipment o In the event of broken glassware, never pick up the C Laboratory Decorum chips with your bare hands regardless of the size of the D Fire E First Aid and Emergency Measures pieces. II Recognizing Common Laboratory Apparatus Use a brush and a dust pan. Clean all broken glass and spilled chemicals neatly. Always read the labels of the reagents you are going to use TWICE and never take more of the reagent than you need. CHEMICAL SAFETY AND LABORATORY RULES o Excess liquid chemicals should be disposed properly. LABORATORY TECHNIQUES Inform your instructor if you have medical conditions that can affect your performance in the lab (e.g., epilepsy, pregnancy, dyslexia, and other conditions that can be LABORATORY APPAREL hazardous in the lab). Laboratory gowns and safety goggles are required in the laboratory at all times. FIRE Long hair should be kept in place. In the event of fire, don’t panic. Do not wear any jewelries such as rings, watches, etc. If a large portion of your clothes catches fire, you could: Sandals, open-toed shoes, high heels, shorts or skirt o Drop on the ground and roll cuts above the knee – not allowed in the laboratory o Use the safety shower Contact lenses – not allowed in the lab due to fumes that o Use the safety blanket might cause them to dry Never use the fire extinguisher on a person. If a fire occurred in a beaker or some other container, cover SAFETY EQUIPMENT it with a watch glass or flame retardant items. Be familiar with the location of the lab safety equipment in Bever move any burning object or used water to extinguish the lab. the chemical fire. o Fire extinguisher, emergency eyewash station, safety Be familiar with the proper utilization of the fire extinguisher shower, and first aid toolbox especially if the fire is large enough to warrant a fuse. Check all safety equipment if they are all still working properly and are loaded or charged. FIRST AID AND EMERGENCY MEASURES For thermal burns, LABORATORY DECORUM o Hold the burnt area under cold water or in contact with Place your coats, books, backpacks, and other personal ice for several minutes. items in the designated place in the laboratory. o Do not apply ointment or bandage. Bring only the materials you are going to use for the day’s o If the burn is large or severe, call a physician at once. experiment in the bench or working area assigned to your For acid on skin, group. o Pat the affected areas immediately with cloth. Always read the upcoming experiments thoroughly to help o Wash with plenty of water, then wash with saturated you perform the experiments correctly and quickly. bicarbonate solution, then again with water. Eating, drinking, smoking, and playing are strictly prohibited For solid organic substance on the skin, in the laboratory. o Wash affected area with rubbing alcohol, then clean Wash your hands frequently during experiment and well with soap and water. certainly at the end of the laboratory period. For minor cuts, Report all chemical spills immediately to your instructor. o Allow them to bleed for a few seconds. o Spills on the bench or floor must be cleaned up o Remove bits or fragments of substances from the instantaneously. wounded area. Report any accidents or injuries to your instructor for o Apply an antiseptic and bandage. immediate remedy. For serious cuts, Perform experiments under the supervision of your o Send a doctor at once. instructor. o Meanwhile, try to stop the bleeding by applying o Any modifications in the procedure, hazards, and pressure with a sterile pad over the wound. safety precautions of the day’s experiment will also be In case of eye accidents, explained by your instructor. o Immediately flush the eyes with a stream of water for Never make unauthorized substitutions. at least 10 minutes. Never smell gases or vapors directly. o Do not attempt any chemical utilization in the eyes for Turn off the gas outlet immediately when not in use. deeper burns that might result to the heat of reaction. Use the film food whenever heating involves large evolution o Heat of reaction – search definition or irritating and hazardous flames. o In all cases, take the patient to the student clinic. Be cautious in using the gas burner when volatile organic In case of poisoning by swallowing, solvents (VOCs) are involved in the experiment. o Dilute the poison as fast as possible by drinking plenty Prevent common accidents by being aware of their causes. of water. o Most hand injuries involve cut, thermal burns, and o Neutralize the poison. chemical burns.  ▪ For acids, induce vomiting by freely giving lukewarm water with 2 tablespoons of salt per glass until the expelled liquid is clear. In case of electric shock, o Remove the source of shock as soon as possible. o Use a dry towel when removing the live wires or equipment. o If the victim is not breathing, administer artificial respiration. o Call a certified first-aider or a physician at once. RECOGNIZING COMMON LABORATORY APPARATUS TEST TUBES, TEST TUBE RACK, & TEST TUBE STIRRING/GLASS ROD & PORCELAIN AND BRUSH STAINLESSS SPATULA Test tubes Stirring/Glass rod o Glassware with rounded bottom designed to contain o Used to guide the transfer of liquids into a container small number of samples for reactions with narrow opening o Cylindrical vessels used to mix, store, and heat Porcelain and Stainless spatula chemicals o Used to transfer solid materials/chemicals from its Test tube rack original container onto a weighing box and other o Used to hold multiple test tubes in an upright position containers o May be plastic or wooden o Use a porcelain spatula when there are reactive o Has vertical wells to organize and support each test substances that can stain or leave deposits on metals. tube Test tube brush (with nylon bristles mounted on a wire) o Used to clean test tubes and other types of narrow mouth laboratory glass wares DROPPER PIPET & THISTLE TUBE Dropper pipet o Used to draw liquid that can then be squeezed out in small drops HARD GLASS TUBE OR IGNITION TUBE, TEST TUBE o Be conscious of squeezing the bulb of the dropper HOLDER, & ALCOHOL LAMP pipet before introducing it to a solution. o Improper use will introduce unnecessary bubbles Hard glass tube or Ignition tube leading to a disturbance of solution. o Primarily used to hold small quantities of substances Thistle tube which will undergo direct heating o For adding chemical solutions to a reaction vessel to o Heavy vault test tubes minimize the risk or a reaction occurring too quickly and o Used for the assessment of directly heated substances bubbling over Test tube holder o Clamp with a spring handle used to hold a test tube o Supports a test tube while heating o Can be made from wood or metal o Squeezing the handle of a test tube holder – causes it to open and grab the test tubes on its end Alcohol lamp o Used as a small heat source o Uses alcohol or spirit as its fuel source to produce and open flame  VOLUMTERIC PIPET, SEROLOGICAL PIPET, & o Elongated neck – used to indicate a specific volume ASPIRATOR at a specific temperature Volumetric pipet Beaker o Used to measure an exact volume of liquid and placing o Used to hold liquids and for mixing, stirring, and heating it into another container chemicals o Pipets – graduated glass tubes used to dispense an o Cylindrical containers with approximate graduations accurate amount of liquid using a rubber aspirator to and a lip to allow ease of pouring liquids draw the solution into the pipet o Has a size capacity to indicate appropriate amount of o Digits on the volumetric pipet – indicates the exact liquid it can contain volume measured by the single graduate mark Graduated cylinder Serological pipet o Primary measuring tool for liquids o Used to transfer milliliter volumes of liquid, from less o Has a ruled scale divided into increments depending than 1 mL up to 50 mL on its size capacity Aspirator o Serves as a vacuum source to draw liquids FLORENCE FLASK & ERLENMEYER FLASK Florence flask MOHR BURET/BASE BURET, GEISSLER o For uniform heating, boiling, distillation, and ease of BURET/ACID BURET, & WASH BOTTLE swirling Mohr Buret or Base Buret o Glasswares with a rounded bottom ensures uniform o Used for titrating alkaline solutions only because acids heat distribution can react with the rubber tubing Erlenmeyer flask o Indicate accurate measurements for titration o Conical flask experiments o Used to contain and mix chemicals o Has a rubber tubing and metal pinch cock o Small neck – used to facilitate mixing without spilling Geissler Buret or Acid Buret o Fitted stoppers – may be used to seal flasks o Used for titrating acids solutions only because alkalies/bases have the property to attack the glass stopcock o Graduated glass tubes that dispense small amounts of liquid by adjusting the stopcock Wash bottle o Squeezable plastic bottle with nozzle o Used to dispense distilled water for rinsing EVAPORATING DISH & HOT PLATE Evaporating dish o A small bowl with a spout used to evaporate excess solvents in a small sample o A shallow open container used to produce a concentrated product Hot plate o Flat surfaced device used for controlled and consistent VOLUMETRIC FLASK, BEAKER, & GRADUATED heating CYLINDER Volumetric flask o Used to prepare solutions to an accurate volume o A calibrated glassware with a single graduated ring on its elongated neck  PORCELAIN CASSEROLE & CRUCIBLE TONG BURET CLAMP, CLAMP HOLDER, & OTHER TYPES Porcelain casserole OF CLAMPS o A small-handled, deep porcelain crucible used for Buret clamp heating and evaporating o Metal equipment used to hold and secure a buret on a o Used to evaporate liquid, concentrate a solution, or to stand dry solid matter o Metal clamps – are connected to the neck of a Crucible tong glassware while the other end is connected to a stand o Used to hold hot objects to ensure stability ▪ Make sure that these are fit tightly and the whole setup is balanced Clamp holder o Metal equipment used to secure laboratory clamps Other types of clamps o Used to hold and secure glassware DISTILLING FLASK, THERMOMETER, CONDENSER, & GLASS ADAPTER Distilling flask o Used to separate mixtures of two liquids with different boiling points o Has a rounded bottom for uniform heating, a long neck serving as the distillation column, and a protruding side IRON RING, GLASS FUNEL, & IRON STAND arm to facilitate condensation Iron ring Thermometer o Metal ring with screw clamp to support containers o Device used to determine temperature Glass funnel o When dealing with thermometers, it should not touch o Used to transfer liquids or fine-grained materials into the surface of the glassware containers with small openings Condenser o Has a wide cone-shaped body and a long narrow stem o Equipment used to condense for the delivery of the filter to a receiving vessel – o Generated vapors are cooled down and are converted preventing loss through spillage into liquid form o Filter paper – should be folded into a cone shape and Glass Adapter wetted with a solvent before pouring the solution to be o Guides the flow of the distillate to the receiving vessel filtered Iron stand o An upright metal rod attached to heavy metal base used to provide stability and support  BUCHNER FUNNEL & FILTERING FLASK WING TOP, RUBBER TUBING, & BUNSEN BURNER Buchner funnel Wing top o Funnel with perforated plate and a vacuum in the flask o Used to adjust the shape of the flame underneath the filter o An accessory used to produce a broad, flat, fan-shaped o Has a flat bottom surface with small holes flame that is required for bending glass tubing ▪ A wetted filter paper is placed on top of this flat Rubber tubing surface before use o Used as passage lines for fluids and gases o Rubber collar – used to fit the Buchner funnel to the Bunsen bruner neck of the filtering flask o Metal heating device connected to a flammable gas o Used for vacuum-assisted filtration source Filtering flask o Produces a single, continuous, open flame by mixing o Büchner flask, vacuum flask, suction flask, side-arm gas with air flask, or Kitasato flask o The amount of air can be adjusted to control the o Thick-walled Erlenmeyer flask with a short glass tube intentinsity, temperature, and size of the flame and hose barb protruding from its neck ▪ Hose barb on its neck – where the vacuum hose is connected o Used for vacuum-assisted filtration ▪ Since reduced pressure is used in the vacuum filtration, thick-walled filtering flask is very essential PINCHCOCK & WIRE GAUZE Pinchcock o Metal clamp used on a flezible tube to regulate the flow a fluid through the tube Wire gauze o Wire screen with ceramic fibered center used to spread the heat of the flame CLAY TRIANGLE, PORCELAIN CRUCIBLE, & o Support containers to prevent breakage due to thermal TRIPOD shock Clay triangle o Triangular wire frame with clay covering used to support crubicle when heated over an open flame Porcelain crubicle o Used for holding chemicals during heating to very high temperatures o Deep cup-shaped vessel with cover to contain smoke particles Tripod o Three-legged metal frame used as a platform  o Ground glass joint of the ioine flask – prevents the PETRI DISH, WATCH GLASS, & SPOT PLATE iodine volatile vapors from escaping, improving the Petri dish accuracy of one’s analysis o Shallow cylindrical glass or plastic flat-bottomed dish Mortal & pestle with lid used primarily to culture microorganisms and o Mortar cells ▪ A vessel in which substances are ground or o Has a shallow, flat, and transparent surface for crushed with a pestle unobstructed viewing of cultures while the versatile ▪ Bowl-shaped where solid substances are placed watch glass has a concave surface o Pestle Watch glass ▪ Tool used to crush, mash, or grind materials in a o Used to cover a beaker or to hold small amount of solid mortar or liquid while they are being weighed ▪ Crushing for mixing purposes or size reduction o Used to devise a gas chamber o Has a concave surface Spot plate o Ceramic or plastic reaction surface containing small wells for spot tests TRIANGULAR FILE, CORK BORER, & PH METER Triangular file o Metal tool for scoring and trimming glass rods o Used to engrave on the glass surface before cutting Cork borer SEPAROTRY FUNNEL & DESICCATOR o Metal tool used for cutting a hole in a cork or rubber SEPARATORY FUNNEL stopper o Used to create a hole where glass tubings or o Glass funnel with a tap at the bottom used for parting thermometers can be inserted immiscible liquid components in a mixture o Employed to separate liquids of different solubilities pH meter and densities o Electric device used to measure hydrogen-ion activity o For the separation of liquids, it utilizes its with wide top of a solution to facilitate shaking and mixing together with the o Essential in monitoring the acidity or alkalinity of a stopcock located at the narrow end solution Desiccator o Sealable glass enclouse used for storage or preservation of moisture-sensitive items o Dessicant – substance that absorbs or attracts moisture from the air causing a state of dryness to prevent the moisture from damaging moisture- sensitive samples ANALYTICAL BALANCE, WEIGHING BOTTLE, & TRIPLE BEAM BALANCE Analytical balance o Accurate and precise instrument used to measure weight in quantitative chemical analysis o When weighing solid substances, ▪ Do not handle the substance to be weighed with IODINE FLASK & MORTAR AND PESTLE bare hands – the moisture, grease, and dirt on Iodine flask your fingers will affect the weight of the substance o Used for the determination of iodine ▪ Do not overload the balance o Has a ground socket and cup-shaped top  ▪ Never place any chemical directly on the balance pan – alaways use a weighing bottle or a weighing box Weighing bottle o Cylindrical glass bottles used for precise weighing of solids Triple beam balance o Instrument used in weight determination that utilizes a stainless-steel pan, beams, and riders END  [TRANS] CHAPTER 1 – GENERAL LABORATORY TECHNIQUES Slaking - adding water to a powder in limited amount at a OUTLINE time until it absorbs and swells, liberating heat and finally I Analytical Chemistry disintegrating into fine powder II Terminology III Analytical Reaction ANALYTICAL REACTION IV Laboratory Techniques External Effects Indicating Reactions Have Taken Place ANALYTICAL CHEMISTRY Formation of a precipitate Analytical Chemistry Dissolution of a precipitate o The branch of chemistry that studies chemical Appearance and disappearance of color in a solution or in composition that involves identifying, separating, a flame quantifying chemical compounds Evolution of gas Divided into two: Development of a characteristic odor o Qualitative Chemistry ▪ Identity of substances Conducted Under Strictly Definite Conditions: ▪ Further divided into two: Proximate Analysis Suitable medium (identifies a compound) & Ultimate/Elementary Temperature of the solution Analysis (identifies elements) o Temperature should be noted since all o Quantitative Chemistry chemicals/compounds have its own properties ▪ Quantity or proportion of a compound Sufficiently high concentrations of a particular ion in solution Prevent contamination of the reagents o Should not put the excess chemicals into the original container o Do not use same dropper to different solutions or else cross-contamination might occur o Water bottles – place where we can put the excess/used chemicals LABORATORY TECHNIQUES Filtration Precipitation Decantation Washing of Precipitate Testing of Solubility of the precipitate Water bath Semi-Micro Analysis Method Sand bath Utilize about 50 mg of solid and 1 mL of test solution Evaporation Based on the volume and amount Precipitation with Hydrogen sulfide gas Flame Test TERMINOLOGY Use of Buchner Funnel Reaction - any process in w/c a new chemical Work involving gas Reagent - a substance used to bring about a reaction Test- laboratory operation to show the presence or absence FILTRATION of some substance, usually some ionic species In this technique, centrifuge is usually used. Confirmatory Test - a test used to identify the ion that gives It is an apparatus that uses centrifugal force to separate characteristic results (if it is really present in the solution) compounds or ions based on their density. Test Solution - contains the ion or substances for which o A high-speed force is used by the machine to achieve tests are made the full separation. o TS Cations - usually prepared from their nitrates or 1. Ensure that the small test tube to be used should chloride salts. not be more than ¾ full. o TS Anions - usually prepared from sodium or 2. Place the small test tube potassium salts. inside the centrifuge. Clear Solution - one that is not turbid 3. Balance the centrifuge Colorless Solution - one that is not colored symmetrically. Residue - the solid that remains after evaporating a mixture Position another test tube or solution to dryness with the same amount of Precipitate - any insoluble substance produced in a liquid on the opposite cup reaction of centrifuge. (shakey Calcination - heating without fusion when not balanced) o heating of solid from high temperature to move volatile 4. Run the centrifuge for 20- substance 30 seconds. 5. Allow the machine to stop by itself.  PRECIPITATION 1. Use a small porcelain casserole Add the precipitate reagent dropwise with constant and heat over a wire gauze using stirring/flicking. a small flame. o Bunsen burner, wire gauze, tripod for indirect contact Test For Completeness Of Precipitation o Produce a concentrated or 1. To the clear supernatant liquid, add 1-2 drops of solid precipitate from a precipitating agent. dissolved substance 2. Precipitate is complete if no more precipitate is formed. 2. Slowly allow the liquid to come in contact with the hot walls 3. In case of precipitation or turbidity, add a few drops more of of the casserole to facilitate. the precipitating reagent. o Should be conducted without boiling. 4. Stir and centrifuge again. 3. Evaporation to Dryness 5. Repeat the procedure until the solution fails to give a o Remove the casserole from the flame while there is still precipitate. a drop or two of the liquid left. ▪ Heat in the casserole will complete the DECANTATION evaporation. A process in which we separate mixtures by removing a liquid layer that is free of a precipitate/solid deposited from PRECIPITATION WITH HYDROGEN SULFIDE GAS a solution. Hydrogen sulfide gas is a colorless gas with a The purpose can be obtained by having a decant, a liquid characteristic of foul odor (rotten egg odor) free particulate, or to recover the precipitate. 1. Compress the bulb and insert the tip of the pipet slightly Sources Of Hydrogen Sulfide Gas below the level of the liquid. Reaction of HCl with FeS (Pyrite) in the Kipps Type 2. Slowly release the bulb. Generator (could yield gases). 3. Lower the tip as the level of the solution drops. 4. When the solution level nears the precipitate, slightly o 𝐅𝐞𝐒 + 𝟐𝐇𝐂𝐥 → 𝐅𝐞𝐂𝐥𝟐 + 𝐇𝟐 𝐒 ↑ tilt the tube. Hydrolysis of thioacetamide in a slightly acidic or basic media at elevated temperature. o 𝐂𝐇𝟑 𝐂𝐒𝐍𝐇𝟐 + 𝐇𝟐 𝐎 → 𝐂𝐇𝟑 𝐂𝐎𝐍𝐇𝟐 + 𝐇𝟐 𝐒 ↑ WASHING OF THE PRECIPITATE To completely remove the impurities to a solution that has been filtered. Procedure: 1. Add the required amount of distilled water or wash 1. Add 10 drops of 10% CH3 CONH2 to be saturated with H2 S. solution to the solid. 2. Stir the mixture and heat in a water bath for 10 minutes. 2. Stir, centrifuge, and decant the wash liquid. 3. The first portion of the washing is combined with the supernatant liquid. FLAME TEST 4. The second portion is discarded. Usually used to identify the presence of relatively small amount of ions in a TESTING FOR SOLUBILITY OF PRECIPITATE compound. 1. Add drop wise the specified reagent to the precipitate. Metal ions are usually the ones that 2. Stir the mixture and observe the quantity of the precipitate. undergoes flame test, but not all metal (mixing rod) ions keep flame colors. 3. If the amount decreases, continue adding the reagent until Non luminous flame – ligther or outer the precipitate dissolves. part of the flame Luminous part – more vistible tip USE OF WATER BATH Procedure: Usually some in a low temperature for a long 1. Clean platinum or nichrome wire with concentrated period of time. hydrochloric acid (to sterilize). o Use a 250 mL beaker 2/3 filled with 2. Place the wire in the non-luminous flame until no color water. is produced. o Direct heating of a small test tube leads 3. The wire is dipped in the acid again. to bumping. 4. The wire is dipped into the compound to be tested and placed back in the flame. USE OF BUCHNER FUNNEL USE OF SAND BATH Buchner funnel 1. Place the mixture in a small vessel. o A vacuum filtration device which has a perforation in 2. Position the small vessel in a bigger vessel the base to retain the filter power and the liquid to pass 2/3 filled with sand. through 3. For solutions which require temperature Use of Buchner funnel to speed up the higher than 100 ℃. rate of filtration. o For products with fine and voluminous precipitate EVAPORATION o Designed for vacuum filtration Seating the filter paper – essential for positioning the filter paper preventing loss of the solid Disconect the hose before turning off the valve – to prevent solution from backwashing into the vacuum system  WORK INVOLVING GASES Gas chamber 1. Use 2 watch glasses in contact with each other. 2. Attach a piece of filter paper moistened with the reagent to the concave surface of the upper watch glass. 3. Place the reaction mixture on the lower watch glasses.