Răspuns:
C+2H2SO4 =>2SO2 +CO2 +2H2O
C⁰-4e=>C⁴ oxidare agent reducator
S⁶+2e=>S⁴reducere agent oxidant 2
C⁰-4e=>C⁴
S⁶+4e=>S⁴
Cu +2H2SO4 =>CuSO4 +SO2 +2H2O
Cu⁰-2e=>Cu² oxidare agent reducator
S⁶+2e=>S⁴ reducere agent oxidant