| Reactions of Potassium |
 Reactions with water |
| Potassium reacts very rapidly with water to form a colourless solution of potassium hydroxide and hydrogen gas. The resulting solution is basic because of the dissolved hydroxide. This reaction is exothermic. Early in the reaction, the potassium becomes so hot that it catches fire and burns with a characteristic pale lilac colour.
|
2K(s) + 2H2O 2KOH(aq) + H2(g) |
| Reactions with air |
| Potassium tarnishes quickly in air due to a reaction of oxygen and moisture. If potassium is burned in air, the result is mainly formation of orange potassium superoxide.
|
| K(s) + O2(g)KO2(s) |
| Reactions with halogens |
| Potassium metal reacts vigorously with all the halogens to form potassium(I) halides. |
| 2K(s) + F2(g)KF(s) |
| 2K(s) + Cl2(g)KCl(s) |
| 2K(s) + Br2(g)KBr(s) |
| Reactions with acids |
| Potassium dissolves readily in dilute sulphuric acid to form solutions containing the aquated K(I) ion together with hydrogen gas.
|
| Reactions with bases |
| Potassium reacts very rapidly with water to form a colourless solution of potassium hydroxide and hydrogen gas. The resulting solution is basic because of the dissolved hydroxide. This reaction is exothermic. Early in the reaction, the potassium becomes so hot that it catches fire and burns with a characteristic pale lilac colour.
|
| 2K(s) + 2H2O2KOH(aq) + H2(g) |
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K(s)