What is the acid or salt, most well-known.It is difficult to find a person who is not holding a bottle of vinegar, or not used in the life of a food product, without which virtually any food seems fresh and tasteless.But what lye?This is the same as the base, or not?How is it different from the acid?Such questions can stump anyone, and therefore allow ourselves to refresh the knowledge that once were in the school.
Alkali - what is this?
Let's start with the fact that the metal compounds to water in chemistry called hydroxides.The substance of this type, formed with ammonium, alkali or alkaline earth metal, alkali is known.In turn, the base - is the electrolyte, which included, in addition to hydroxide ions (OH-), no other anions.Thus, we can say that the alkali - is any soluble base.To form a metal hydroxide can only subgroups Ia and IIa (those that go after the calcium).Examples of such compounds may serve as sodium lye (Formula NaOH), caustic bariat (Ba (OH) 2), potassium hydroxide (KOH), cesium hydroxide (CsOH), etc.They represent a solid white substance, which have a high hygroscopicity.
alkalis dissolved in the water of these compounds is accompanied by significant heat.In Group Ia alkali strongest - a cesium hydroxide and a Group IIa - radium hydroxide.An example of this type of weak connections can serve ammonia and slaked lime.Caustic alkali are soluble in ethanol and methanol.In the solid state these substances absorb water from the air and carbon dioxide and slowly transformed into carbonates.The most important property of the alkali is that as a result of its reaction with the acid salt is formed - this feature is often used in industry.Through these connections can pass electric current, and therefore they are often used as electrolytes.Was prepared using the alkali chloride electrolysis, or by reacting the alkali metal oxides and water.The industry commonly uses the first method and the second is used mostly for producing slaked lime.In an alkaline environment dissolves fat, and this property is widely used in the manufacture of soap.A number of reasons can destroy plant and animal tissues, irritate the skin and destroy clothes.Alkalies can react with certain metals (e.g. aluminum), and are able to protect steel from corrosion.They are resistant to heat - sodium hydroxide can be melted and brought to a boil, but it will not decompose.This is very different from an alkali insoluble bases, some of which (for example, silver hydroxide) decomposes even at room temperature.As acid, these substances require great care and high demands to comply with safety recommendations.For eye protection when working with alkali usually wear glasses.Keeping them is allowed only in special vessels - drinking container that will not fit.