[Bill]

I'm helping my son with his eighth grade science fair project.  We are fueling a rocket car with a vinegar/baking soda mixture.  We are testing the reaction speed by changing the pressure,temperature, and concentration levels.  I cannot find imformation on the reaction taking place between the vinegar and baking soda that creates the pressure.  I know the vinegar has H+ ions and the baking soda+water is OH- but what is happening when the two are combined  that creates the pressure?

[budullewraagh]

Vinegar (CH3COOH)  + Baking Soda (NaHCO3)  --->  Sodium Ethanoate (CH3COONa)  +  Carbonic Acid (H2CO3)

The bubbles are carbon dioxide and are produced by the decomposition of the carbonic acid (which occurs rapidly)
H2CO3  --->  H2O  +  CO2

[Mitch]

good answer scooby snack given.

[billnotgatez]

Many documents give CH3COONa nomenclature to be Sodium Acetate instead of Sodium Ethanoate.

[billnotgatez]

Greetings Bill,

Although I did not find a good site explaining the pressure change, I did find some good sites that have information on the vinegar and baking soda reaction.

http://antoine.frostburg.edu/chem/senese/101/reactions/faq/print-classify-vinegar-bakingsoda.shtml
http://antoine.frostburg.edu/chem/senese/101/thermo/faq/vinegar-baking-soda-enthalpy.shtml

Maybe someone will give a better explanation than carbon dioxide is released to answer you pressure question.

Regards,
Bill

[billnotgatez]

http://antoine.frostburg.edu/chem/senese/101/gases/faq/co2-from-vinegar-and-baking-soda.shtml

[Bill]

Hey guys,   thanks for all the help  The project is coming together nicely now.