UCSB Science Line
Sponge Spicules Nerve Cells Galaxy Abalone Shell Nickel Succinate X-ray Lens Lupine
UCSB Science Line
Home
How it Works
Ask a Question
Search Topics
Webcasts
Our Scientists
Science Links
Contact Information
We did the lab for Halloween where you add 18M sulfuric acid to sugar(sucrose) and get carbon left in the test tube. My question is does the acid act as a catalyst for the breakup or do the H+ ions hydrate the -OH groups on the sucrose? I know the waste product still has to be neutralized which is why I think it is acting as a catalyst.
Answer 1:

No, it does not act like a catalyst.Sulfuric Acid acts as a dehydrating agent, removing the water from the sucrose according to this reaction:

Excess H2S04

C12H22011---------------------> 12C + 11H20

The hydration of the Sulfuric acid creates heat (exothermic reaction). This is the driving force of the reaction.Sulfuric acid is hydrated.Like you said, the acid is reacting with the OH groups of the sucrose.
The waste product still has to be neutralized because it is still an acid,although less strong now because it is diluted.


Click Here to return to the search form.

University of California, Santa Barbara Materials Research Laboratory National Science Foundation
This program is co-sponsored by the National Science Foundation and UCSB School-University Partnerships
Copyright © 2015 The Regents of the University of California,
All Rights Reserved.
UCSB Terms of Use