Many chemicals are incompatible with each other.
According to Laboratory Safety for Chemistry Students [PDF], by Robert H. Hill and David C. Finster:
Incompatible chemicals are combinations of substances, usually in concentrated form, that react with each other to produce very exothermic reactions that can be violent and explosive and/or can release toxic substances, usually as gases.
Care should be taken when handling, storing, or disposing of chemicals in combination. Below is a short list of common laboratory chemicals and the substances with which they are incompatible.
|Acetic acid||nitric acid, peroxides, permanganates|
|Acetic anhydride||ethylene glycol, hydroxyl-group-containing compounds|
|Ammonium nitrate||acids, flammable liquids, powdered metals, finely divided organic or combustible materials|
|Chlorate salts, such as sodium or potassium chlorate||acids, ammonium salts, metal powders, finely divided organic or combustible materials|
|Chlorine||ammonia, butane, hydrogen, turpentine, finely divided metals|
|Hydrocarbons||bromine, chlorine, peroxides|
|Hydrogen peroxide||combustible materials, copper, iron, most metals and their salts, any flammable liquid|
|Nitric acid, concentrated||acetic acid, acetone, alcohol, flammable substances, such as organic chemicals
Note: There have been many explosions from inappropriate or inadvertent mixing of nitric acid with organic chemicals in waste containers.
|Oxalic acid||silver, mercury|
|Oxygen||flammable materials, hydrogen, oils|
|Phosphorus, white||air, oxygen|
|Potassium permanganate||ethylene glycol, glycerol, sulfuric acid|
|Sodium (alkali metals: lithium, sodium, and potassium)||arbon dioxide, water, alcohols|
|Sodium nitrite||ammonium salts|
|Sulfuric acid||chlorates, perchlorates, permanganates|