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高中化学中氨的催化氧化实验,是个难度较大的演示实验。按课本讲的办法来操作,效果极不明显,而且铂丝价格昂贵,不易找到。我们参考有关资料,作了一些改进,现介绍如下: 改进部份: 1.用电线中的细铜丝代替铂丝作催化剂,价廉易得且催化效果很好。 2.用纯氧代替空气。取10克氯酸钾与少量二氧化锰混和加热制氧,贮存于球胆内备用。 实验装置: ①充满氧气的球胆。②广口瓶,内装浸透浓氨水(约3毫升)的脱脂棉球。③20×200毫米反应管(最好用硬质玻璃管,也可用裁去底部的大试管代替),中部放一团细铜丝,进气端装入用玻璃纤维裹好的碱石灰颗粒,出气端装入用玻璃纤维裹好的氯化钙颗粒。④锥形瓶。⑤盛有紫色石蕊试液的试管。 操作步骤及现象: 1.检查装置的气密性。
The catalytic oxidation of ammonia in high school chemistry is a difficult demonstration experiment. According to the textbook approach, the effect is not obvious, and platinum wire is expensive and difficult to find. We have made some improvements with reference to the relevant information and are now presented as follows: Improvements: 1. The use of fine copper wires in electric wires instead of platinum wires as catalysts is cheap and easy to obtain and the catalytic effect is very good. 2. Use pure oxygen instead of air. Ten grams of potassium chlorate and a small amount of manganese dioxide were mixed and heated to produce oxygen, which was stored in the bladder for use. Experimental setup: 1 Oxygen filled bladder. 2 A wide-mouth bottle containing a cotton ball soaked in concentrated ammonia (about 3 ml). 320 × 200 mm reaction tube (preferably hard glass tube, can also be used to cut the bottom of the large test tube instead), put a small group of fine copper wire, the inlet side is loaded with glass fiber wrapped soda lime particles, out of gas The ends are loaded with calcium chloride particles wrapped in glass fibers. 4 Erlenmeyer flask. 5 Test tube containing purple litmus test solution. Operation steps and phenomena: 1. Check the airtightness of the device.