Laboratory Archives | School Portal NG

Which apparatus? You wouldn’t dream of trying a chicken using a spoon, or of drying your hair in over a stove! In everyday life, we need to use the right tools for the job we are doing. The same is true in the science lab. There are lots of types of different chemical apparatus, all designed to do different jobs. Using the right apparatus makes your practical work safer. The pictures below show some of the apparatus you will be expected to know about and use in a chemistry laboratory. Burette Made from accurate uniform wall tubing to insure the stipulated capacity tolerances. Features durable, permanent markings; fine, sharp lines and large, easy-to-read numbers. The stopcock is carefully ground and finished to assure a leak-free operation. A burette is used to deliver solution in precisely measured, variable volumes. To fill a burette, close the stopcock at the bottom and use a funnel. You may need to lift up on the funnel slightly, to allow the solution to flow in freely. Pippette A pipette is used to measure small fixed amounts of solution very accurately. A pipette bulb is used to draw solution into the pipette. A pipette has a mark that shows how much volume it can draw. It cannot be used for transferring any other volume unless the one specified on it. Beakers Made of heat resistant borosilicate glass, withstanding temperatures up to 680°C, the beaker features a large marking spot, graduations and pouring spout. The primary function of a beaker is to hold and work with liquids. If graduated, it can serve to make approximate measurements of liquid volume. The beaker is made of specialized glass so it can be heated and cooled without breaking. This type of glass makes the beaker brittle and it must be handled carefully. Evaporating Dish This porcelain item resembles a shallow bowl with a spout. Evaporating dishes are traditionally used to evaporate solvent to concentrate a solution; however they can also be used to hold sand for a sand bath, as a small water bath, or as a drying dish (like a watch glass). Glass rods These rods are used in all science laboratories to stir and mix substances. 5mm in diameter and 200 mm (approx. 8 inches) in length. Condenser This apparatus is made of high quality borosilicate glass. It can withstand up to 600°C temperature. This instrument is suitable for pure water distillation and other kinds of distillation in the laboratory. The Graham condenser has both inner and outer joints. For use in vacuum distillation, the jacket is sealed to the inner tube. Drip tip is located at the end. Hose connections are 10mm overall diameter. Top opening is 29mm. Cold water enters from the lower tap and exits from the top. Googles. Eye protection is a priority in any science laboratory setting. When fumes are involved (and you will be working with A LOT of those in chemistry) and well as possible splashing, you generally need something that does not allow air to vent through. Protective goggles that are meant specifically for chemistry have plugs to keep those fumes/liquids out. It's also why you have eyewash stations in your lab in case someone does not wear their goggles and need to wash the chemicals out of their eyes. Stirrer The function of a stirrer is to agitate liquids for speeding up reactions or improving mixtures. Measuring Cylinder Graduated or measuring cylinders are specifically designed to make accurate liquid volume measurements. The volume is read from the lowest portion of the meniscus of the liquid; that is, the lowest portion of the convex dip of the liquid as it sits in the graduated cylinder. Graduated cylinders are available in a number of sizes. Crucible Tongs Used for handling or manipulating hot crucibles and similar apparatus. They have corrugated tips for easy handling; riveted joints and the finger openings are large enough for a firm grip. They are made of plated steel. Mortar and Pestle Mortar and pestles are used to grind solids into powders. Test Tube The function of a test tube is to hold a small experiment, which would be used to conduct an investigation. The test tube is made of specialized glass so it can be heated and cooled without breaking. This same type of glass makes the test tube brittle and it must be handled carefully. Thermometer The thermometer is an instrument for determining temperature. Most laboratory thermometers are calibrated in the SI scale (degrees Celsius). Thistle Tube Thistle tubes are usually used in experiments involving semi-permeable membranes. Osmosis and diffusion can be illustrated well. Thistle tubes are also used in separation experiments as well as other chemical applications. Balance The function of a balance is to mass objects. NOTE: If the device is measuring an object using springs against gravity, the devise is correctly referred to as a scale and its measurements are described as weight not mass.] A balance uses a comparison of a known substance or calibration with the unknown object to determine the unknown object's mass. Fume Hood Fume hoods protect laboratory workers from fumes and potentially dangerous chemical reactions by continuously vacuuming air out of the lab and by providing a glass shield. Experiments can be clearly seen by the user, yet the user is protected from splatter and harmful fumes. Funnel A funnel is used to aid in the transfer liquid from one vessel to another. Dropper A dropper is used to transfer a small volume of liquid (less than one mL). Volumetric Flask A volumetric flask is used to measure very precisely one specific volume of liquid (100 ml, 250 ml, etc., depending on which flask you use). This flask is used to prepare a solution of known concentration. A volumetric flask should not be used to heat substances or store solutions, and you should avoid pipetting directly from the volumetric flask. Our volumetric flasks provide precise volume measurement. The necks are tooled and have glass stoppers. The graduation line is sharp and permanent and there is an easy to read marking spot. For solutions of solid in a liquid solvent, first dissolve the solid in a vessel other than the volumetric flask, in case the solid must be heated or crushed in order to be dissolved. After the solid dissolves, pour the liquid into the volumetric flask and use the solvent to rinse all of the solution from the vessel into the flask. However, if the solid is known to be very soluble, it may be added directly to the flask. Clay Pipe Triangle Used for supporting crucibles and dishes when heating on gas or alcohol burners. It has three porcelain pipe stem attached to galvanized iron wire. Bunsen burner A Bunsen burner is a laboratory device designed to heat substances for various experiments. In essence, a Bunsen burner is a small gas burner with an adjustable flame, manipulated at the base by controlling the amount of gas and air admitted into the burner. The design of a Bunsen burner includes a vertical metal tube which is connected to a weighted base. The base includes a nozzle to connect with a fuel source, as well as a gas valve and a flue adjuster to control how much air is admitted through small air holes at the base of the tube. The gas mixes with air at the bottom of the tube and then rises to the top of the Bunsen burner, where it can be lit with a match or lighter. In general, the scientist should make sure that hair and clothing are secure, and unlikely to fall into the flame. In addition, flammable chemicals should be kept away from the Bunsen burner, and someone should remain by the burner at all times to supervise it. The flexible rubber hose connecting the Bunsen burner to the gas nozzle on the lab bench should also be secure, with no evidence of leaking, and people should be cautious about touching things which have been exposed to the often considerable heat of a Bunsen burner, especially glass objects. Flame A typical flame consists of three zones that are easily distinguished. - The innermost zone, a non-luminous cone, is composed of a gas-air mixture at a comparatively low temperature. - In the second, or luminous, cone, hydrogen and carbon monoxide are produced by decomposition and begin to react with oxygen to form water and carbon dioxide, respectively. In this cone the temperature of the flame—about 590° to 680° C is great enough to dissociate the gases in the flame and produce free particles of carbon, which are heated to incandescence and then consumed. The incandescent carbon produces the characteristic yellow light of this portion of the flame. - Outside the luminous cone is a third, invisible cone in which the remaining carbon monoxide and hydrogen are finally consumed. If a cold object is introduced into the outer portions of a flame, the temperature of that part of the flame will be lowered below the point of combustion, and unburned carbon and carbon monoxide will be given off. Thus, if a porcelain dish is passed through a candle flame, it will receive a deposit of carbon in the form of soot. Operation of any kind of flame-producing stove in a room that is unventilated is dangerous because of the production of carbon monoxide, which is poisonous. All combustible substances require a definite proportion of oxygen for complete burning. (A flame can be sustained in an atmosphere of pure chlorine, although combustion is not complete.) In the burning of a candle, or of solids such as wood or coal, this oxygen is supplied by the surrounding atmosphere. In blowpipes and various types of gas burners, air or pure oxygen is mixed with the gas at the base of the burner so that the carbon is consumed almost instantaneously at the mouth of the burner. For this reason such flames are non-luminous. They also occupy a smaller volume and are proportionately hotter than a simple candle flame. The hottest portion of the flame of a Bunsen burner has a temperature of about 1600° C. Such flames have a bluish-green cone in place of the luminous cone. If the oxygen supply is reduced, such flames have four cones: nonluminous, bluish-green, luminous, and invisible. Hazard Warning Symbols Hazardous Material Safety Reference Sheets and Material Safety Data Sheets are produced to remind laboratory users of the potential hazards of the materials at hand. The table below shows some common hazard symbols and some of the chemicals on which these may be found. Chemicals We deal with chemicals all day long. A chemical is any substance used or produced in a chemical process. Water is a chemical produced in a chemical reaction between hydrogen and oxygen. It is used for chemical processes of life. Natural materials, e.g. Cotton, wood are produced by chemical processes of living things during their lives. Natural materials are also chemicals. Man made or synthetic materials are produced by man. Plastics and nylon are some synthetic materials. Everything in the universe is made of chemicals. Some have chemical names, as well as more common names. Can you think of three more chemicals that have similar common names and chemical names?

NAMES OF LABORATORY APPARATUS

CHEMISTRY LABORATORY