K2Cr2O7+K2S+H2SO4

The reaction you have provided is a redox reaction between potassium dichromate (K2Cr2O7), potassium sulfide (K2S), and sulfuric acid (H2SO4). The equation for this reaction is as follows:

K2Cr2O7 + K2S + H2SO4 -> Cr2(SO4)3 + K2SO4 + H2O

In this reaction, potassium dichromate is reduced to chromium(III) sulfate, and potassium sulfide is oxidized to potassium sulfate.