Water is the most essential and abundant compound on Earth, and in laboratory and industrial settings, it's more precisely defined by its purification method and grade. Known chemically as H2O, water is referred to under several names depending on how it's processed, including distilled water, deionized (DI) water, and purified water. Across pharmaceuticals, analytical chemistry, manufacturing, and general laboratory work, water serves as the foundational solvent and reagent that underpins nearly every other process.

What makes water valuable in professional settings isn't the compound itself but its purity. A single molecule with the same formula can range from tap-grade to ultra-pure LC/MS grade, and that distinction determines whether it's suitable for drinking, industrial cooling, or trace-level chromatographic analysis. Selecting the correct grade is often the difference between reliable results and contaminated data or product.

Water carries a straightforward safety profile relative to most laboratory chemicals. It is non-hazardous under standard classification systems, requires no specialized handling precautions, and is not subject to DOT hazardous material regulations. That simplicity, combined with the range of certified grades available, makes it one of the most frequently ordered products across research, production, and industrial supply chains.

• Compound Name: Water

• Synonyms/Common Names: Distilled water, deionized (DI) water, purified water, dihydrogen oxide

• Chemical Formula: H2O

• CAS Number: 7732-18-5

• Molar Mass: 18.02 g/mol

• Density and Behavior Relative to Standard Reference Colorless, odorless, tasteless liquid at room temperature

Water has a density of 1.000 g/cm³ at 4°C, a value so consistent that it serves as the reference standard against which the specific gravity of other liquids and solids is measured. This reference role makes water density calculations a baseline check in quality control and formulation work. Deviations from this figure in a sample typically indicate dissolved solids or contamination rather than a change in the water itself.

Water is a clear, colorless, odorless liquid widely used in laboratory, pharmaceutical, and industrial applications. It functions as a solvent, reagent, cleaning agent, and process fluid in analytical testing, chemical production, equipment cleaning, and formulation. U.S. laboratories and manufacturers sourcing water by grade and purity contact Lab Alley at 512-668-9918 for product selection and ordering support.

Water boils at 100°C (212°F) at standard atmospheric pressure and freezes at 0°C (32°F). These fixed transition points are why water is used as a calibration reference for thermometers and temperature-sensitive lab equipment. Pressure changes will shift these values, which is a relevant consideration for high-altitude or vacuum-based laboratory processes.

Water functions as a universal solvent, readily dissolving and mixing with a wide range of polar compounds, salts, and organic molecules. It does not mix with most nonpolar organics, including oils and hydrocarbons, which is the basis for many separation and extraction techniques. This dual behavior, highly miscible with polar substances and immiscible with nonpolar ones, defines its role in nearly every solvent-based application.

Pure water has a neutral pH of approximately 7.0 at 25°C, reflecting its balanced concentration of hydrogen and hydroxide ions. Ultra-pure grades such as LC/MS and HPLC water can show slight pH variation due to dissolved atmospheric CO2, which forms trace carbonic acid on contact with air. This is a normal characteristic of high-purity water rather than an indicator of contamination.

Water is chemically stable under normal storage and handling conditions and is non-flammable. It reacts with highly reactive metals such as alkali metals and with strong dehydrating agents, though these reactions are not a concern in typical laboratory or industrial use. Under GHS criteria, water is not classified as hazardous, reflecting its stable and predictable chemical behavior.

Water from Lab Alley is available in USP Grade, HPLC Grade, LC/MS Grade, and Deionized Water Lab Grade to meet laboratory, analytical, pharmaceutical, and industrial requirements. Packaging ranges from 500 mL bottles to 275-gallon bulk containers to support research, manufacturing, and commercial supply needs.