Potassium iodide reacts with oxygen.

In the equation, iodine ions are oxidized only in the presence of oxygen. If there is water, potassium oxide will continue to react with whom, just like sodium oxide. After all, potassium is more active than sodium. The reaction should be like this:

KI+O2→I2+ K 2O

K2O+H2O→ Potassium hydroxide+oxygen

Generally, potassium iodide will react when placed in humid air. Iodine oxide will not be generated because it will continue to react with water to generate potassium hydroxide. Also, under certain conditions, the price of potassium ion will rise.

Water in the air also participates in the reaction, redox reaction, I rises from-1 to +5 and 0 respectively, and O in O2 drops from 0 to -2.

Extended data:

chemical reaction

Because iodine is a mild reducing agent, iodine ion I? Can be oxidized to I2 by strong oxidants such as chlorine gas;

2 KI (aqueous solution)+Cl2 (aqueous solution) → 2 KCl+I2 (aqueous solution)

This reaction can be used to extract iodine from natural products and verify the existence of chlorine. Air can also oxidize iodine ions. When the KI sample is left for a long time and washed with dichloromethane, it can be found that the color of the extraction layer is purple (the color of iodine dissolved in organic solvents). Hydroiodic acid (HI) is a strong reducing agent in acidic environment.

Potassium iodide can also directly reduce concentrated sulfuric acid into hydrogen sulfide;

8KI+9h2so 4 →( khso 4)84h2o+4i 2+H2S？ [3]?

Like other iodized salt, KI reacts with iodine to form I3? ：

KI(aq) + I2(s) → KI3(aq)

Different from I2, I3? Salt is easily soluble in water, and iodine can be used in redox titration through this reaction. KI3 aqueous solution, namely Lugo solution, can be used as disinfectant and corrosive agent for gold surface.

Iodine ions in potassium iodide can form dark yellow precipitate silver iodide with silver ions (see photolysis, which can be used to make high-speed photographic films), so silver nitrate can be used to test the existence of iodine ions.

Potassium iodide+silver nitrate → silver iodide+potassium nitrate

Organic chemistry KI is an iodine source in organic synthesis. A useful application is the preparation of iodoaromatic compounds by aromatic diazonium salts. For example:

C6H5NH2？ ==NaNO2+HCl== C6H5NN+

C6H5NN+？ ===KI== C6H5I

Potassium iodide reacts with bromine to produce iodine and potassium bromide: Br2+2KI=2KBr+I2.

In addition, potassium iodide, as an iodine source, can also be used as a catalyst in nucleophilic substitution reactions, thus enhancing the activity of chlorinated hydrocarbons, brominated hydrocarbons or mesylate as nucleophilic substitution substrates.

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