Final answer:
Primary amines form hydrogen bonds with water, making them soluble up to five carbons. They can act as bases and react with strong acids to make soluble salts. Amines have important physiological roles and applications in medicine.
Step-by-step explanation:
When primary amines are added to water, they engage in hydrogen bonding with the water molecules due to the presence of nitrogen, which has a lone pair of electrons. This results in the formation of soluble complexes for amines with up to five carbon atoms. Amines with more than five carbons tend to be slightly soluble or insoluble in water due to the increased hydrophobic character of the longer carbon chain. Furthermore, primary amines can act as bases when dissolved in water, accepting protons from water molecules to form ammonium ions and hydroxide ions, increasing the pH of the solution. For example, methaneamine in water would yield methaneammonium ions and hydroxide ions. Also noteworthy is the interaction of amines with strong acids, which can lead to the formation of water-soluble amine salts, essential in various applications, including medicine.
The importance of amines in health and medicine is significant due to their presence in amino acids and other biologically active compounds. For instance, histamine plays a critical role in the body's response to injury or allergies, and antihistamines like diphenhydramine are used to counteract these effects.