1) Prepare a lesson carnestly before the experiment. Clarify the related basic principle, sequence of the operation, and safety measures in the experiment. 2) Put on the working clothes before entering the laboratory. Record the experimental phenomena and data. 3) Keep the floor neat. Don’t throw anything into the water trough so as to avoid stops up. 4) After every experiment, the students being on duty shall take responsibility for cleaning up the laboratory, inspecing the switch of water and electricity, and closing the window. 5) write the experiment report according to the primary record and turn in. Laboratory safety regulations
1) Corrosive acids and alkali must be treated carefully, and be sure not to splash on clothes, skin and eyes. While diluting strong sulfuric acid, the acid should be poured slowly into the water with stirring, but not water into the acid. 2）It’s not allowed to handle solid drugs with the hand directly. Don’t mix different kinds of chemicals arbitrarily. Basic operations in chemical experiment
1. Get knowledge of all kinds of common glassware, grasp the names and uses of them such as 1) Beaker. prepare solution, when heated, it must be puted on the asbestos gauze. 2) Erlenmeyer flask. heat samples or titration. when heated, must open the stopper. puted on the asbestos gauze. 3) Rounded(flat)-Bottom flask. heat liquid or for distillation. It can be heated in the heating jacket. 4) Washing bottle. filled with distilled water or washing liquid. 5) Measuring cylinder. It is mainly used to measure liquid roughly. 6) Volumetric flask. prepare accurate volume standard solution or unknown concentration to be determined. It can not be heated directly, it must be heated by hot water bath 7) Weighing bottle. determine water content of sample or oven dry, weigh primary standard substance. 8) Reagent bottle. narrow- necked bottle store liquid. wide-mouthed bottle store solid reagents. Brown bottle easy to decompose when seeing light. can not be heated. Don't store basic solution for long time. 9) Dropping bottle. The solution need to dropwise.
10) Separating funnel. separate two mutual non-homogenous liquids. check leak . 11) Condenser. distillation. Coiled shape condensing low boiling point liquid. from the bottom up. 12) Filter flask. receive filtrate when suction filtration.
13) Watching glass. cover beaker or other containers.
14) Desiccator. dry small amount of samples. bottom placed by silicone. blue turn to red when absorb water. 15) measuring pipet. transfer accurately a certain quantity of liquid. It has scale. 16) transfer pipette. transfer accurately a certain quantity of liquid , no scale. 17) Burette. titration. check leak. Acid solution with stopcock, basic solution with rubber pipe. 2. Practice the use of the glassware provided in the plastic box, with a focus on Practicing operation of measuring pipet, transfer pipette, Volumetric flask and Burette. 1) Use of measuring pipette and transfer pipette. Transfer pipette has no scale, there is a bulb in the middle of it. measuring pipet has scale division. Firstly, wash. washed by tap water and then by distilled water. Keep it level, Rotate. hold the pipette by right hand and suction ball by left hand. Secondly, rinse. Pour some solution into a beaker, draw the solution and rinsed three times. draw the solution to the level beyond the scale and press the mouth of the pipette with first finger of right hand immediately. wipe dry. Thirdly, adjust the solution level. Hold a beaker with left hand and lean the beaker against the pipette. beaker 45º , pipette vertical. Loosen finger slowly, rotate the pipette untill the lowest surface of solution drop to the same level as the scale. 2) Use of volumetric flask. We can dilute the concentrated solution to a certain volume or prepare a certain volume solution of some solids. Leakage check: fill in tap water, stopper and press the...