Observing the Reactions of Sulfuric Acid

Refer to 9.1 Practical skills Practical Skills

We will examine the reactions of sulfuric acid as an oxidising agent and as a dehydrating agent.


  • One 250mL beaker
  • Sucrose
  • Concentrated sulfuric acid


  1. Pour sucrose into an empty beaker, filling it up to one third of capacity.
  2. Place the beaker in a fume cupboard.
  3. Pour 25mL of concentrated sulfuric acid into the beak and step away.

NOTE: Concentrated sulfuric acid and the fumes produced as EXTREMELY dangerous. Sulfuric acid, especially concentrated is both exothermically hydrating and a strong oxidant against living tissue.

Expected Results:

It may take a few seconds for the beaker to chow any change, but once it does the result will be rather quickly achieved. The sucrose should be replaced by a much larger carbon structure (looks porous), which demonstrates sulfuric acid as a dehydrating agent.

Next, carbon is oxidised, forming carbon dioxide, sulfur dioxide and water. These fumes are dangerous in quantity, the experiment must be performed in either a well ventilated area, barring a fume cupboard.

C(s) + 2H2SO4(l) → CO2(g) + 2SO2(g) + 2H2O(l)