Importance of Water

Solvent

Water is an excellent solvent, which means that many chemicals dissolve easily into it (referred to as dissolved species, Fig. 4.2).

Dipolar

Water molecules have one end that is more negatively charged, and one end more positively charged (Fig. 4.1), allowing it to bond or complex with most charged species and with itself.

Benefits

Makes water a useful cleaning agent, and important transporter of chemicals in all living things

Costs

Water can easily be contaminated with undesirable chemicals

Figure 4.1: Dipolar nature of water molecule and intermolecular hydrogen bond. The two white hydrogens are more positive than the red oxygen (which is not sharing two of its electrons). After U. Arizona Biology Project.

Figure 4.2: Dissolution of NaCl in water. After U. Arizona Biology Project.