AB + CD AC + BD
where A, B, C, and D are atoms or ions. The reaction between vinegar and baking soda can be written as a double displacement reaction if carbonic acid (H2CO3) is considered a product:HC2H3O2(aq) + NaHCO3(aq) NaC2H3O2(aq) + H2CO3(aq)
Here A, B, C, and D are H+, C2H3O2-, Na+, and HCO3-, respectively. [1, 2]However, carbonic acid readily decomposes into carbon dioxide and water,
H2CO3(aq) CO2(aq) + H2O()
and the carbon dioxide can escape from the solution as a gas.The combined equation is
HC2H3O2(aq) + NaHCO3(aq) NaC2H3O2(aq) + H2O() + CO2(g)
which doesn't fit neatly into one category, since it is a double displacement followed by a decomposition. When you encounter a reaction that is difficult to classify, consider the possibility that it may be the net or total equation for a sequence of steps.Copyright © 1997-2010 by Fred Senese
Comments & questions to fsenese@frostburg.edu
Last Revised 02/23/18.URL: http://antoine.frostburg.edu/chem/senese/101/reactions/faq/print-classify-vinegar-bakingsoda.shtml