Consider the reaction, C+2H2SO4→CO2+2SO2+2H2O ; Equivalent weight of carbon and sulphuric acid are respectively

C + H2SO4 →CO2 + SO2 +H2OIncrease in oxidation number of 'C' = 4Decrease in oxidation number of 'S' of sulphuric acid = 2Equivalent weight of carbon= 124=3 ;Equivalent weight of sulphuric acid= 982=49 ;