Task: Text Categorization
Input (English): Question: A mixture of iron (III) chloride and potassium hexacyanoferrate (III) (potassium ferricyanide) is used to detect extremely small amounts of hydrogen peroxide in the water. The presence of H2O2 causes, after a short time, an intense dark blue color. This is because hydrogen peroxide: 
 Options:  <0> It reduces hexacyanoferrate (III) to hexacyanoferrate (II). <1> Oxide to hexacyanoferrate (III). <2> Oxide to iron (III) chloride. <3> Peroxo-cyano form complexes of Fe (III). <4> Oxidize cyanocomplexes to complex cyanate.
Output (English): chemistry