50.0 mL of 0.500 M HCN and 25.0 mL of 0.500 M sodium hydroxide combination can be used to make a buffer with a pH of 4.2. The KK
an of benzoic acid, C6H5COOH, is 6.5×10-5 and the an of hydrocyanic acid, HCN, is 4.9×10-10.
Benzoic acid
A white (or colourless) solid with the chemical formula C6H5CO2H, benzoic acid is pronounced: "bnzo.k." The simplest aromatic carboxylic acid is this one. The term comes from gum benzoin, which was the substance's exclusive source for a very long period. Many plants naturally contain benzoic acid, which is used as an intermediary in the formation of numerous secondary metabolites[9]. Benzoic acid salts are employed as food preservatives. An essential starting point for the industrial synthesis of many other chemical compounds is benzoic acid. The term "benzoates" refers to the salts and esters of benzoic acid.
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