Concentrated sulfuric acid (~96% H2SO4) is a corrosive liquid with strong water-binding properties.
In this experiment, the effect of concentrated sulfuric acid on paper (main component cellulose (C6H10O5)n) and sugar (sucrose-C12H22O11) was shown.
1) In the first experiment, sulfuric acid was dropped on paper (cellulose). The surface of the paper turned black, suggesting the formation of a layer of charcoal:
(C6H10O5)n(s) → 6nC(s) + 5nH2O(l)
At higher temperatures and longer duration, concentrated sulfuric acid turns carbon into carbon dioxide (CO2):
C(s) + 2H2SO4(l) → CO2 (g) + 2SO2(g) + 2H2O(g)
2) When concentrated sulfuric acid was poured on sugar, the white sugar turned to a brownish mass and eventually became black i.e. was transferred to charcoal:
C12H22O11(s) → 12C(s) + 11H2O(g)
Caution! Concentrated sulfuric acid is a highly corrosive liquid! Avoid contact with skin!