【精品】中学化学一些规律和小结(国外英文资料).doc

【精品】中学化学一些规律和小结(国外英文资料) Seven principles of chemical laboratory operation in high school With the following seven principles of operation sequence, you can answer the test question correctly. From the bottom up principle. C1 = laboratory method, for example, assembly sequence generator is: put away the hob machine to set the alcohol lamp, according to the alcohol lamp position fixed good iron circle - asbestos network - fixed round bottom flask. From left to right principle. Assembling complex devices should follow from left to right. The assembly sequence is as follows: the device goes to the bottle and the beaker. The principle of fixing is first. Plug the plug in the flask before the flask is fixed, so that the flask will not be fixed and the machine will not be too tight or too hard to damage the instrument. Solid first principle. In the example above, the reagent MnO2 in the flask should be loaded before the flask, so as not to damage the flask when the solid is put in. In any case, the solid reagent should be added to the container before it is fixed. The liquid post-it principle. Liquid medicine is added after the flask is fixed. In the above case, the hydrochloric acid should be slowly added in the split funnel after the flask is fixed. Prior airtightness (preloading) the principle. The principle of the post-light alcohol lamp (when all fixtures are finished). The author: chemsir 2006-11-19 12:24 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- Answer: 【 fine 】 middle school chemistry a few rules and small knot Second, the use of thermometers in high school chemistry experiments and which experiments need thermometers The temperature of the reaction mixture: this type of experiment needs to measure the exact temperature of the reaction mixture, so the thermometer should