KHC4H4O6 + NaHCO3 = KNaC4H4O6 + H2O + CO2.
The carbon dioxide evolved escapes through the dough, thus making it light and porous.
Citric acid (H3·C6H5O7). This acid occurs in many fruits, especially in lemons. It is a white solid, soluble in water, and is often used as a substitute for lemons in making lemonade.
Lactic acid (H·C3H5O3). This is a liquid which is formed in the souring of milk.
Oleic acid (H·C18H33O2). The derivatives of this acid constitute the principal part of many oils and liquid fats. The acid itself is an oily liquid.
ETHEREAL SALTS
When acids are brought in contact with alcohols under certain conditions a reaction takes place similar to that which takes place between acids and bases. The following equations will serve as illustrations:
KOH + HNO3 = KNO3 + H2O,
CH3OH + HNO3 = CH3NO3 + H2O.
The resulting compounds of which methyl nitrate (CH3NO3) may be taken as the type belong to the class known as ethereal salts, the name having been given them because some of them possess pleasant ethereal odors. It will be seen that the ethereal salts differ from ordinary salts in that they contain a hydrocarbon radical, such as CH3, C2H5, C3H5, in place of a metal.