Write the reaction equations: oxide (||) – methanol – sodium methylate – methanol – methanal

Let’s carry out the solution of the chain of transformations. Let’s compose the reaction equations:
4Cr + 3O2 = 2Cr2O3 – reaction of the compound, chromium oxide was obtained (3);
Cr2O3 + 3H2SO4 = Cr2 (SO4) 3 + 3H2O – ion exchange, chromium sulfate is formed;
Cr2 (SO4) 3 + 3Br2 + 14KOH = K2Cr2O7 + 6KBr + 3K2SO4 + 7H2O – redox reaction (ORR), potassium dichromate was obtained;
4K2Cr2O7 = 4K2CrO4 + 2Cr2O3 + 3O2 – decomposition, potassium chromate salt was obtained.
Chromium compounds are toxic. Potassium chromate is used in the textile industry for dyeing fabrics. Potassium dichromate is used as a strong oxidizing agent.