原文: Top 10 Amazing Chemical Reactions

Chemical reactions are part of our daily lives. From cooking in the kitchen, to driving a car, these reactions are commonplace. This list is aimed at some of the more exotic and amazing reactions that most of us have not seen or experienced. My knowledge of science is limited, so if I have made a blunder in my descriptions, please let me know so that I can correct them! Here are the top 10 amazing chemical reactions. Do not try these at home (but if you do - send us the video clips!)

Sodium is a highly combustible element and the addition of water can make it explode. In this video we see a drop of water added to a small piece of sodium in a flask filled with chlorine gas. The distinctive yellow color of the light emitted is due to sodium’s ‘D lines’ - this is often used in street lighting. This experiment produces a great deal of heat. When you combine sodium and chlorine, you get sodium chloride - common salt.

Magnesium ignites easily and burns very brightly. In this experiment, you see magnesium ignited in a shell of dry ice - frozen carbon dioxide. Magnesium is able to burn in carbon dioxide and nitrogen. Because of its brilliant light, it was used in early photographic flashes, and it is still used in marine flares and fireworks.

Potassium Chlorate is a compound containing potassium, chlorine and oxygen. It is often used as a disinfectant and in fireworks and explosives. When potassium chlorate is heated to melting point, any item added to it will cause a rapid disintegration in the form of an explosion (as we see in the video above). The gas coming off the potassium chlorate is oxygen. Because of this, it is often used in airplanes, space stations, and submarines as a source for oxygen. A fire on the space station Mir was attributed to this substance.

When a superconductor is cooled to below its transitional temperature, it becomes diamagnetic: this is when something is repulsed from a magnetic field rather than drawn in to it. This discovery by Meissner has lead to the concept of frictionless transportation, as an object could be “floated” along a track rather than “attached” to it by wheels.

Sodium acetate, when heated and cooled, becomes supersaturated in water. When it comes in contact with another object it re-crystalizes. This reaction also causes heat, and so this has a practical use in heat pads. Sodium acetate is also used as a preservative, and also gives salt and vinegar chips their distinctive taste. It is referred to in foods as E262 or sodium diacetate.

Superabsorbent polymers (also known as hydrogels) are able to absorb extremely large amounts of liquid relative to its own mass. For this reason, they are used in the commercial production of diapers, and incontinence garments, and other fields requiring protection from water or liquids such as underground cabling.

Sulfur Hexafluoride is a colorless, odorless, non-toxic and non-flammable gas. Because it is over 5 times denser than air, it is able to be poured in to open containers and light weight objects can float on it as if it were water. Another fun use for this harmless gas is through inhalation; when inhaled, it lowers the voice drastically - the exact opposite of helium. You can see that effect here:

The reason that your voice is lowered when you inhale sulfur hexafluoride is that the weight of the gas slows the sound waves produced in your vocal tract to just under half the speed of the sound. Helium works in the opposite way.

When helium is cooled cooled to -271c, it reaches the lambda point. At this stage (as a liquid) it is known as Helium II. Hellium II is a superfluid. When it flows through even capillaries of 10−7 to 10−8-m widths it has no measurable viscosity. In addition, it will creep up a container (as it seeks out a warmer area) seemingly against the effects of gravity. Just watch the clip above and be amazed!

Thermite is aluminum powder and a metal oxide which produces an aluminothermic reaction known as a thermite reaction. It is not explosive, but it can create short bursts of extremely high temperature. A thermite reaction is initiated with some type of detonator and it can burn at temperatures of thousands of degrees. In the clip above we see an attempt to “cool” the thermite reaction by dumping it in a vat of liquid nitrogen.

The Briggs-Rauscher reaction is known as an oscillating chemical reaction. According to Wikipedia: “the freshly prepared colorless solution slowly turns an amber color, suddenly changing to a very dark blue. This slowly fades to colorless and the process repeats, about ten times in the most popular formulation, before ending as a dark blue liquid smelling strongly of iodine.” The reason this occurs is that the first reaction causes certain chemicals to be released in to the liquid, which then, in turn, spark a second reaction, and the process repeats itself until exhausted.

译文: 10大令人惊异的化学反应！（有视频）

     化学反应是我们日常生活的一部分。从厨房烹饪到驾车行驶，化学反应无处不在。这里列举了我们不太常见或经历过的化学反应，奇异惊人。如果我在的叙述时出现小错误，请帮我纠正它！这里是10大惊人的化学反应。请不要在家中尝试。（不过如果你尝试了，请把录像寄给我们吧！）

10

     钠元素极易燃烧，遇水可致爆炸。录像中我们看到在一个充满氯气的细颈瓶中，将一滴水滴在小块钠上。瓶内释放明显的亮黄色气体，通常使用与路灯中。这个试验产生大量热。将钠与氯结合得到氯化钠——就是食用盐。

      镁极易点燃，燃烧时有耀眼的强光。这个试验中你将看到一块镁在干冰上燃烧——干冰是固体二氧化碳。镁还能在二氧化碳与氮上燃烧。由于它的耀眼强光，被用于早期的摄影闪光灯中。如今它仍然使用于海洋弹与烟火的制造中。

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氯酸钾与糖的反应

    氯酸钾是钾、氯、氧的结合，常用作消毒剂，用于烟火与炸药中。当氯化钾加热到熔点时，任何与之反应的物质都将随着爆炸而迅速分解（正如我们在上述录像中看到的）。从氯化钾中释放出的气体就是氧气。这是由于这一点，氯化钾作为氧气的来源通常被用于飞机、太空站以及潜水艇中。它是Mir太空站的起火原因。

    当一个超导体被冷却降低了它的转化温度，它就变得有抗磁性：就是说在一个磁场内两物相互排斥而不是相互吸引。这是由迈斯纳发现的，现在的无摩擦运输就是运用这个原理，就如火车可以“漂浮”在轨道上而不是通过轮子与轨道摩擦。

     醋酸钠，加热或冷凝时，遇水呈超饱和态。当与其它物质相结合便可以再结晶。这个试验同样释放热量，所以可用于热垫制造。醋酸钠也可用作防腐剂，也能使薯条带有独特味道。这就是用于食物中的双乙酸钠。

    高吸水性树脂（也称水凝胶），由于高吸水性可以极大程度地吸收大量液体。因此，它们通常被用于如一次性尿布、防水外套等商品中，还有一些需要防水的领域中比如地下电缆。

    六氟化硫是一种无色、无味、无毒的非易燃气体。它的密度是空气的5倍，所以能把它倒在开口容器中，轻的物体可以漂浮在它上面就好像在水里一样。还有一种有趣的玩法就是将这个无毒气体吸入体内，当你吸了它，它能神气般地降低你的嗓音——这是与氦气完全相反的效果。看看下面的视频：

  当你吸了六氟化硫你的嗓音被降低了是因为它的重量减缓了声波通过声道的速度。而氦气的效果恰恰相反。

3

超流体 氦

   当氦被冷却到-271度时，它就达到了lambda点，这时（作为液体）就变成了氦II。氦II是一种超流体。当它流经7至8米宽的毛细管时，它是没有粘性的。另外，它似乎能克服地球引力沿着容器壁流动（因为它对热气体有反应）。看看上面这个令你诧异的视频吧！

  铝热是铝粉，一种金属氧化剂，能产生我们所谓的铝热反应。它不是爆炸只是短时间内突然爆发高温。铝热反应可由一些起爆剂引发，在数千度的高温下燃烧。在上面的视频中我们看到，为了让铝热反应“降温”而浇入大量液氮。

1

    Briggs-Rauscher反应是一种变色的化学反应。维基百科上这样解释：刚刚准备的无色溶液慢慢变成了琥珀色，突然又变成了深蓝色。随后又慢慢退成无色并重复上述过程，结束之前形成了深蓝色形成强烈气味的碘。”发生这一变化的原因是第一次反应产生的化学成分再次进入液体，然后引发了第二次反应，随后一直重复这个过程直到成分耗尽。