Encyclopedia > Half-reaction

  Article Content

Half-reaction

Half reactions are obtained by considering the change in oxidation states of individual substances involved in a reduction/oxidation reaction.

Consider the reaction below:

(1) Cl2 + 2Fe2+ -> 2Cl- + 2Fe3+

The two elements involved, iron and chlorine, each change oxidation state - iron from 2+ to 3+, chlorine from 0 to 1-. There are then effectively two half-reactions occurring. These changes can be represented in formulas by inserting appropriate electrons in to each half-reaction:

 (3) Fe2+ -> Fe3+ + e- 
 (4) Cl2 + 2e- -> 2Cl-   

In the same way given two half-reactions it is possible, with knowledge of appropriate electrode potentials, to arrive at the full (original) reaction.

See also: Electrode potential



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
242

... 190s 200s 210s 220s 230s - 240s - 250s 260s 270s 280s 290s Years: 237 238 239 240 241 - 242 - 243 244 245 246 247 Events Patriarch Titus[?] succeeds Patriarch ...

 
 
 
This page was created in 26.9 ms