CHEMICAL AND PHYSICAL PROPERTIES
| Physical Description | Sodium hydroxide, solid appears as a white solid. Corrosive to metals and tissue. Used in chemical manufacturing, petroleum refining, cleaning compounds, drain cleaners. |
|---|---|
| Color/Form | White, orthogonal crystals |
| Odor | ... Odorless ... |
| Taste | Detection - the minimum physical intensity detection by a subject where he or she is not required to identify the stimulus but just detect the existence of the stimulus - in water: 8.00X10-3 mol/L. |
| Boiling Point | Very high (USCG, 1999) |
| Melting Point | 604 °F (USCG, 1999) |
| Solubility | 111 % (NIOSH, 2023) |
| Density | 2.13 at 68 °F (USCG, 1999) - Denser than water; will sink |
| Vapor Pressure | 0 mmHg (approx) (NIOSH, 2023) |
| Stability/Shelf Life | CONTAINERS OF LYE MUST BE TIGHTLY CLOSED TO PREVENT CONVERSION TO SODIUM CARBONATE BY CARBON DIOXIDE OF AIR. |
| Autoignition Temperature | Not flammable (USCG, 1999) |
| Decomposition | When heated to decomposition it emits toxic fumes of /sodium oxide/. |
| Viscosity | 4.0 cP at 350 °C |
| Corrosivity | Very corrosive (caustic) to ... aluminum metal in presence of moisture |
| Heat of Combustion | SRP4: Non-combustible |
| Heat of Vaporization | 175 kJ/mol at 1388 °C |
| pH | Strongly alkaline (1 % solution) |
| Surface Tension | At 18 °C: 74.35 dynes/cm (2.72 wt%), 75.85 dynes/cm (5.66 wt%), 83.05 dynes/cm (16.66 wt%), 96.05 dynes/cm (30.56 wt%), 101.05 dynes/cm (35.90 wt%) |
| Polymerization | SRP4: Not polymerized |
| Refractive Index | Refractive index at 589.4 nm: 1.433 at 320 °C; 1.421 at 420 °C |
| Dissociation Constants | SRP4: Completely dissociated |
| Other Experimental Properties | 5% solution (wt/wt): density: 1.056, FP: -4 °C, BP: 102 °C. 10% solution (wt/wt): density: 1.111, FP: -10 °C, BP: 105 °C. 20% solution (wt/wt): density: 1.222, FP: -26 °C, BP: 110 °C. 30% solution (wt/wt): density: 1.333, FP: 1 °C, CP: 115 °C. 40% solution (wt/wt): density: 1.434, FP: 15 °C, BP: 125 °C. 50% solution (wt/wt): density: 1.530, FP: 12 °C, BP: 140 °C |
| Chemical Classes | Other Classes -> Bases |
COMPUTED DESCRIPTORS
| Molecular Weight | 39.997 g/mol |
|---|---|
| Hydrogen Bond Donor Count | 1 |
| Hydrogen Bond Acceptor Count | 1 |
| Rotatable Bond Count | 0 |
| Exact Mass | 39.99250893 g/mol |
| Monoisotopic Mass | 39.99250893 g/mol |
| Topological Polar Surface Area | 1 Ų |
| Heavy Atom Count | 2 |
| Formal Charge | 0 |
| Complexity | 2 |
| Isotope Atom Count | 0 |
| Defined Atom Stereocenter Count | 0 |
| Undefined Atom Stereocenter Count | 0 |
| Defined Bond Stereocenter Count | 0 |
| Undefined Bond Stereocenter Count | 0 |
| Covalently-Bonded Unit Count | 2 |
| Compound Is Canonicalized | Yes |
PRODUCT INTRODUCTION
description
At room temperature, sodium hydroxide is a white crystalline odorless solid that absorbs moisture from the air. It is a manufactured substance. When dissolved in water or neutralized with acid it liberates substantial heat, which may be sufficient to ignite combustible materials. Sodium hydroxide is very corrosive. It is generally used as a solid or a 50% solution. Other common names include caustic soda and lye. Sodium hydroxide is used to manufacture soaps, rayon, paper, explosives, dyestuffs, and petroleum products. It is also used in processing cotton fabric, laundering and bleaching, metal cleaning and processing, oxide coating, electroplating, and electrolytic extracting. It is commonly present in commercial drain and oven cleaners.