CHEMISTRY PRACTICAL (CBSE) I. Commonly used apparatus in the laboratory
IN E TE D R U N L AT A IO B N Z AL
Test tube : It is a hollow cylindrical glass tube with one open and one closed end. It is used for carrying out chemical tests and studying reactions in solutions.
Boiling tube : It is a hard glass test-tube made of pyrex which is resistant to chemicals. It is used for strong heating.
Beaker : It is a flat bottomed cylindrical glass vessel with a pouring lip. It is used for holding and pouring different liquids and also for mixing solutions during chemical reactions.
Flask : These are glass vessels of various shapes used for different purposes.
(i) Flat-bottomed flask : It is used for storing solutions and carrying out reactions at room temperature. (ii) Round-bottomed flask : It is used for carrying out reactions at high temperatures. (iii) Conical flask : It is used for carrying out volumetric titrations, storage of liquids and mixing of solutions.
Glass tube : It is a hollow tube made of glass, used for transporting liquids and gases. A number of glass tubes connected to each other makes a delivery tube. Glass rod : It is a solid cylindrical rod made of glass and is used for stirring solutions. Test-tube holder : It is a metallic clamp fixed on a wooden handle. It is used for holding a test-tube while heating or when a chemical is added. Funnel : It is a cone-shaped glassware with a narrow hollow stem at the lower end. It is used for filtration purposes during which a filter paper made into a cone is wetted and placed inside it. Stand : It contains an iron rod with a heavy rectangular iron base and one or more clamps mounted on the rod, which can be raised or rotated. It is used for holding apparatus such as flasks, test-tubes, etc. or supporting funnels.
Test-tube stand : It is a wooden or plastic stand with holes of different sizes and upright pegs.
The test tubes are kept in the upright position through the holes. The washed test tubes are inverted on the pegs for drying. 2
Watch glass : It is a concave shaped glass plate. It is used as a lid and for weighing chemicals, etc.
China dish or evaporating dish or crucible : It is glazed porcelain dish available in various sizes. It is used during evaporation of solutions and crystallisation of salts. Spirit lamp : It is a glass or brass vessel containing alcohol (spirit) through which passes a cotton wick. It is used for heating and can be carried to any place for the purpose. But now a days, it has become outdated.
Bunsen burner : It is a specially prepared burner in which natural gas is used as a fuel for burning. It is used for heating various chemicals, solutions metals, etc.
Claypipe triangle : It is a triangular frame of steel wires covered with china claypipes. It is used to support a china dish or a crucible.
Wire gauge : It is a rectangular wire mesh provided with a thin sheet of asbestos. It helps to distribute the heat evenly under the glass apparatus and thus prevents it from cracking.
Tripod stand : It is an equilateral cast iron triangle mounted on three legs. It is used to support a wire gauze and glass apparatus such as flasks, beakers, etc.
Measuring apparatus : These are graduated glass apparatus used for measurement of liquids.
(i)
Measuring cylinder : It is used for measuring fixed volume of a liquid.
(ii)
Burette : It is used to measure the volume of liquids filled in it by allowing it to come out dropwise from the tap.
(iii)
Pipette : It measures the volume of liquids by sucking the liquid from the top.
Gas jar : It is a cylindrical glass vessel used for collecting gases and performing chromatographic analysis.
Thistle funnel : It is a specially designed glass funnel with a long hollow stem. It is used for pouring a liquid reactant in a sealed reaction vessel.
Deflagrating spoon : It consists of a long iron wire with a spoon at one end. It is used to test the action of gases on heated metals and non-metals.
Separating funnel : It is a funnel with a leak-proof stopper at one end and a stop cock at the other end. It is used for separating two immiscible liquids by dropping them intermittently.
Trough : It is a wide mouthed, flat-bottomed circular vessel made of glass or china. It is used as a container.
Beehive shelf : It is a clay vessel provided with two outlets one at the side and the other at the top. It is used for collecting gases by the downward displacement of water.
Retort : It consists of a glass apparatus with a round bottom flask and a hollow glass tube. It is used for carrying out distillation experiments.
Condenser : It is a double walled glass tube with openings at both ends and provided with an inlet and an outlet. It is used for condensing vapours of liquids during distillation.
Dessicators : It is a vessel packed with deliquescent or hygroscopic chemicals like calcium chloride or silica gel. It is used for drying chemical substances or keeping them free from moisture.
Weighing bottle : It is a small glass bottle with flat-ends, straight walls and a ground glass stopper. It is used for weighing chemicals in it.
Reagent bottle : It is a glass bottle provided with an air-light glass stopper. It is used for storing liquid reagents.
