Reactivity spontaneous ignition

Chemical Reactivity - Reactivity with Water. Decomposes slowly but the reaction is not hazardous Reactivity with Common Materials Corrodes metals slowly. If mixed with combustible materials or finely divided metals, mixture can spontaneously ignite or become unstable by friction Stability During Transport Sable Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Metallic nickel is a hard, lustrous, silvery white metal, which in its bulk form is resistant to attack by air and water at ordinary temperatures. However, powdered nickel is reactive in air and may spontaneously ignite. 

The gaseous WP (P4) is distilled from the furnace by condensing with water. The WP allotrope that is formed by this process is a white waxy solid with a m.p. of 45 °C that should be kept under water to prevent its contact with air where it spontaneously ignites because of its extreme reactivity. It is also known as yellow phosphorus because most commercially-produced material exhibits yellow coloration. Red phosphorus (RP) is thermodynamically more stable than the white... 

Two conditions can give rise to the spontaneous combustion of a fuel. One condition involves contact of the material with air. The other is the spontaneous ignition of an unstable self-reactive substance when it is kept at a sufficiently high temperature. Silane (SiH 4 ) and phosphine (PH 3 ) are the examples of the former case, and a mixed atmosphere of air and nickel carbonyl(Ni(CO) 4 ) or carbon disulfide (CS 2 ) are examples of the latter. 

Spontaneously Ignitable Substances and Water—Reactive Substances... 

A marked contrast is observed in the behaviour of the simplest aromatic hydrocarbon-air mixtures at high pressures. No cool-flame phenomena or an ignition peninsula in the (p-Ta) diagram are observed. These are found only when sufficiently reactive aliphatic side-chains are associated with the aromatic ring. Burgoyne et al. [129] showed this to be the case for n-propylbenzene in a closed vessel (Fig. 6.18). The ortho- and meta-isomers of the xylenes also showed a similar reactivity. Benzene, toluene and ethylbenzene were found to undergo spontaneous ignition at temperatures only above 700 K. 

Although the ability to cope with complex mixtures of fuels may be some way off, dealing with alkane mixtures is certainly within our grasp. However, there appears to be one key aspect that requires clarification. From the evidence in Section 6.4, it is clear that the longer chain n-alkanes, such as n-heptane, can undergo spontaneous ignition at very low-temperatures. This is in marked contrast to the lower reactivity of the shorter n-alkane chains such as n-butane, or of highly branched isomers... 

Uranium is reactive chemically, igniting spontaneously in fluorine and, at about 250°, in chlorine, bromine and iodine vapour. It combines with sulphur at 500° and nitrogen at 1000°. The metal dissolves readily in hydrochloric and sulphuric acids giving salts nitric acid renders the metal passive. In this uranium resembles the metals of Group VIA. 

---