Chemical Reactions

A + BC->B + AC

Single Displacement

In a single displacement reaction, one element replaces another similar element in a compound. Using an activity series, it is possible to predict which elements displace each other.

chlorine(sq) + sodium iodide(aq)->iodine(s) + sodium chloride(aq)
Cl2(sq) + NaI(aq)->I2(s) + 2NaCl(aq)

Application

Single displacement reactions are commonly used in metallurgical processes. For example, in the Thermite process, metal oxides (such as of chromium, manganes or barium) are combined with aluminum to extract the pure metal. barium oxide(s) + aluminum(s)->aluminum oxide(s) + barium(s)
3BaO(s) + 2Al(s)->Al2O3(s) + 3Ba(s)

Impact

The Thermite process is necessary to obtain the pure forms of many metals, but is also very dangerous because it produces a large amount of heat. In addition, the process may sometimes happen by accident, for example, when abrasive grinding and cutting wheels are used with aluminium, producing a mixture of oxides capable of violent explosive reactions.src