Dry Method
Hazards
- Use care with concentrated sulfuric acid.
- The fumes given off in this reaction are very irritating.
Chemicals and Solutions
- 85 g granular sugar
- 60 mL Sulfuric acid, conc.
Materials
- disposable 7 oz. poly beaker
- phototray
- 100 ml graduated cylinder
- glass stirring rod
Procedure
Do this demonstration at the end of class so it can be removed immediately.
- Measure 85 g sugar into poly beaker.
- Add 60 mL concentrated H₂SO₄ to sugar (After a couple of minutes the sugar turns black and an intense odor of burnt sugar will be noticeable).
Discussion
The reaction:
\( \ce{ C12H22O11 + 11H2SO4 -> 12C + 11H3O+ + 11HSO4- } \)
\( \ce{ C + 2H2SO4 -> CO2 + 2H2O + 2SO2 } \)
Disposal
Remove the demonstration to a hood and allow it to gas off. Once it has finished gassing off send to EH&S labeled as 95% carbon, 5% sulfuric acid.
Wet Method
Hazards
- Use care with concentrated sulfuric acid.
- The fumes given off in this reaction are very irritating.
Chemicals and Solutions
- 2 M sucrose solution
- Sulfuric acid, conc.
Materials
- 1 - disposable 7 oz. poly beaker
- 1 - phototray
- Graduated cylinders, 50 ml and 100 ml
Procedure
Do this demonstration at the end of class so it can be removed immediately.
- Measure 50 ml H₂SO₄ into graduated cylinder.
- Measure 60 ml sucrose into 100 ml cylinder.
- Combine the sucrose and sulfuric acid carefully in the polybeaker.
Discussion
The reaction:
\( \ce{ C12H22O11 + 11H2SO4 -> 12C + 11H3O+ + 11HSO4- } \)
\( \ce{ C + 2H2SO4 -> CO2 + 2H2O + 2SO2 } \)