Describe what happens when any of the first four carboxylic acids dissolve in water.

When the first four carboxylic acids—methanoic acid, ethanoic acid, propanoic acid, and butanoic acid—dissolve in water, they undergo ionization to form carboxylate ions and hydrogen ions. This process results in the solution becoming acidic due to the release of H⁺ ions. The extent of ionization varies among these acids, with ethanoic acid being a weak acid that partially ionizes, while methanoic acid is slightly stronger. This behavior illustrates the characteristic properties of carboxylic acids in aqueous solutions.