Water reaction with potassium metal

BORIC ACID (10043-35-3) BH3O3 Aqueous boric acid is a weak acid incompatible with alkali carbonates hydroxides strong reducing agents, including metal hydrides, nitrides, sulfides, and alkali metals. Violent reaction with potassium metal. Contact with acetic anhydride forms a heat-sensitive explosive. On small fires, use water fog. 

Pyrrohdinone forms alkaU metal salts by direct reaction with alkaU metals or their alkoxides or with their hydroxides under conditions in which the water of reaction is removed. The potassium salt prepared in situ serves as the catalyst for the vinylation of 2-pyrrohdinone in the commercial production of A/-vinylpyrrohdinone. The mercury salt has also been described, as have the N-bromo and N-chloro derivatives (61,62). 

The reaction of potassium metal with water to generate hydrogen gas, shown in Figure 19-4, is highly spontaneous ... 

However, the latter reaction occurs faster because of the increased acidity of water (K. value of 1 x 10 ). Likewise, similar reactions occur with potassium metal. 

DOT CLASSIFICATION 6.1 Label Poison SAFETY PROFILE Poison by inhalation and intravenous routes. Moderately toxic by ingestion and subcutaneous routes. An irritant. Questionable carcinogen with experimental carcinogenic data. Flammable when exposed to heat or flame. Moderately explosive by spontaneous chemical reaction. To fight fire, use water, CO2, dry chemical. Dehalogenation by reaction with alkalies, metals, etc., will produce spontaneously explosive chloroacetylenes. Violent reaction with NaK aUoy + bromoform. Mixtures with potassium are very shock-sensitive explosives. When heated to decomposition it emits highly toxic fumes of Cl". See also CHLORINATED HYDROCARBONS, ALIPHATIC. 

The reaction of potassium metal with water is spontaneous because a negative AH and a positive AS both contribute to a negative Gibbs energy change. 

BISMUTHBROMIDE or BISMUTHTRIBROMIDE (778-58-8) Reacts with moist air, water, steam, forming hydrogen bromide and bismuthoxybromide. Violent reaction with potassium. Attacks many metals in the presence of moisture. 

Incompatibilities and Reactivities (Sodium-potassium alloy + bromoform), alkalis, metals, water [Note Hydrolysis produces dichloroacetic acid. Reaction with alkalis metals produces spontaneously explosive ohioroacetylenes.] ... 

A more efficient method for decomposing most sulphur compounds is to heat them with sodium or potassium, and then test the solution of the product for sulphide. The test is rendered sensitive by heating the substance with potassium in an ignition tube, dissolving the melt in water, and testing for sulphide by the nitroprusside or methylene blue reactions (see under sulphides. Section 4.6, reactions 6 and 7). Heating substances with potassium metal is a DANGEROUS operation and must be carried out with appropriate equipment under supervision. 

Chemical reactions take place at different speeds. Rusting, the reaction of iron with oxygen and water is a slow process, whereas the reaction of potassium metal with water is explosively fast. Reaction speeds are more properly referred to as reaction rates . The study of the rate of reactions (and of the factors controlling reaction rates) is known as chemical kinetics. 

Water is the oxidizer in flaming reactions with potassium, rubidium, or cesium metal, which explosively burst into flame on contact. A plumsized piece of potassium thrown into water as a joke was said to have killed a German university student in the early part of the century. Sodium will not burst into flame when thrown onto cold water as long as the piece of metal can skim freely over the surface of the water. The moment it attaches itself to the wall of the vessel or is purposely held... 

You would expect this reaction to proceed as written, because potassium metal (K) is well above hydrogen in the activity series. In fact, potassium metal reacts violently with water, which contains only a very small percentage of ions. Imagine the reaction of potassium metal with a strong acid like HCl ... 

Write an equation for the reaction of potassium metal with water. 

The reaction is more vigorous in a solution of potassium amide in ammonia than in ammonia alone. Other reactions with non-metals like sulfur, involving an increased concentration of solvent anion, are more complex. They are similar to those in water, since, like the hydroxyl ion, the amide ion does not readily lose electrons completely. 

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