The violent reaction of sodium and water: experiment wisely
How sodium behaves in water
Chemical experiments are diverse in their depth, complexity and effectiveness. Any list of the most impressive experiments must include the “pharaoh’s snake” or the interaction of snake poison with human blood. But chemists also like to try more dangerous experiments, one of which is the reaction of water and sodium.
Abilities of sodium
Sodium is an extremely active metal which enters into a reaction with many well-known substances. The reaction with sodium often takes place violently, accompanied by a considerable release of heat, combustion and sometimes even explosions. Working safely with the substance requires a precise understanding of its physical and chemical characteristics.
Sodium is not very hard in its structure, and is distinguished by the following characteristics:
- low density (0.97 g/cm³);
- low melting point (97.81 °С).
The metal, which oxidizes swiftly in air, should be stored in sealed containers under a layer of Vaseline or kerosene. Before conducting the experiment with sodium and water, cut off a piece of sodium with a fine scalpel, remove the piece from the container with tweezers and thoroughly clean the kerosene from it with filter paper.
Warning! All the tools must be dry!
You must wear protective glasses when working with the metal, as the smallest careless step may lead to an explosion.
The reaction of water and sodium: a history of studying explosions
The reaction of water and sodium was first studied by scientists at the Czech Academy of Sciences under the leadership of Pavel Jungwirth. The experiment of the detonation of sodium and water, which had been known since the 19th century, was thoroughly analyzed and described.
The reaction of sodium and water involved immersing a piece of the metal in ordinary water, and gave ambiguous results: sometimes there was an explosion, sometimes there was none. Later the reason for the differing results was found – the instability was caused by the sizes and forms of the pieces of sodium used.
The greater the dimensions of the metal, the more powerful and dangerous the reaction of sodium and water became.
A slow-motion film of the process of interaction showed that five milliseconds after the sodium was immersed in water, the metal “shriveled”, releasing hundreds of “needles”. The metal electrons that instantaneously entered the water lead to an accumulation of a positive charge in the metal: the repulsion of positive particles tears up the metal, causing the “needles” to appear. At the same time, the area of the metal increases, which is what causes such a violent reaction.
Here you’ll find safe and entertaining experiments with sodium compounds.
The reaction of sodium and water in the laboratory
It is easy to realize the reaction of water and sodium in the laboratory. Fill a crystallizer three quarters full of water, and add several drops of phenolphthalein. Throw a piece of sodium the size of half a pea into the resulting mixture.
The alkaline metal immediately enters into a reaction, and the heat causes the sodium to melt, turning into a “silvery” drop, which moves swiftly over the surface of the water, making hissing noises.
In the course of the reaction, an alkali will form, leaving a crimson trail behind the piece of sodium. At the end of the experiment, practically all the water in the crystallizer will have turned a crimson shade.
The reaction of water and sodium requires the scientist to observe all safety measures strictly: wear protective glasses, and try to stay at a certain distance from the crystallizer. Even the smallest errors may lead to an explosion. It is dangerous for the tiniest particle of sodium or alkali to get in the eyes.
Warning! Don’t try to repeat these experiments without a professional supervision!