How does sodium acetate make a basic solution in water?
Sodium acetate creates a basic solution in water through a process known as hydrolysis. When the salt dissolves, it separates into its constituent ions: the sodium ion () and the acetate ion ().
In this aqueous environment, water molecules react with the acetate ions to form acetic acid and hydroxide ions (). While acetic acid can dissociate back into acetate and hydrogen ions, this occurs only to a very small extent. Consequently, the solution retains a significant concentration of hydroxide ions, which causes it to exhibit basic properties, such as turning red litmus paper blue.1
Under the BrønstedâLowry definition, the acetate ion acts as a base because it has a tendency to accept a proton to reform its conjugate acid, acetic acid. The resulting equilibrium constant for this reaction is termed the hydrolysis constant and is equal to the ion product of water () divided by the acidity constant () of acetic acid.23