Water appears as a clear, nontoxic liquid composed of hydrogen and oxygen, essential for life and the most widely used solvent. Include water in a mixture to learn how it could react with other chemicals in the mixture. Water is an oxygen hydride consisting of an oxygen atom that is covalently bonded to two hydrogen atoms. It has a role as an amphiprotic solvent, a member of greenhouse gas, a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite and a mouse metabolite. It is an oxygen hydride, a mononuclear parent hydride and an inorganic hydroxy compound. It is a conjugate base of an oxonium. It is a conjugate acid of a hydroxide.

1. In daily life, when related to machinery and electrical equipment, distilled water is mainly used for its non-conductivity, ensuring stable operation and extending the service life of electrical appliances.

2. In the pharmaceutical industry, distilled water functions due to its hypotonic effect. It is used to rinse surgical wounds, causing any residual tumor cells on the wound surface to swell, rupture, necrose, and become inactive, thus preventing tumor implantation and growth on the wound.

3. In school chemistry experiments, distilled water is required in some cases because it contains no electrolytes, free ions, or impurities. Specific analysis is needed to determine whether its non-conductivity, hypotonic effect, or non-reactivity (absence of other ions) is being utilized.