Sodium Hydroxide

Reactions at Interfaces As a Source of Sulfate Formation in Sea-Salt Particles

“…In the case of NaOH, the O/Na ratio is greater than unity. This indicates that even under the vacuum conditions during the analysis, there is water associated with the highly hygroscopic NaOH, consistent with the known formation of hydrates (17,18). In the case of NaOCl, the Cl/Na ratio is less than one and there are substantial amounts of oxygen in the particles (19).…”

“…The SEM data reported here indicate that NaOH forms a shell around the NaCl. Sodium hydroxide is very hygroscopic and forms a stable hydrate at 298 K (17,18). As the salt particles are transported away from sources of the oxides of sulfur and nitrogen and their associated acids, the OHformed in the interface reaction may not be fully neutralized.…”

Bases and Basic Materials in Chemical and Environmental Processes. Liquid versus Solid Basicity

“…In practice, alkali metal hydroxides (in particular sodium hydroxide, also called "caustic", and potassium hydroxide, or "caustic potash") allow the preparation of quite dense (1-1.5 g/mL) and poorly volatile (1-13 Torr at rt) solutions with pH in the range 7-15.5. Two percent solutions (∼0.5 M) have pH ∼ 13, while the commercial 50% NaOH solution, whose melting point is near 15 °C, 55,56 has pH ∼ 15.28, density 1.540 g/mL at 0 °C and 1.469 g/mL at 100 °C, and a partial pressure of water of 0.9 Torr at 20 °C. The partial deprotonation of very weak acids characterized by pK a ∼ 20-25, such as most carbonyl compounds, can be obtained with these solutions.…”

Bases and Basic Materials in Industrial and Environmental Chemistry: A Review of Commercial Processes

“…In this system, there are two maxima in the melting point corresponding to NaOH·3.5H 2 O (i.e., ∼39% NaOH, T m ≈ 15.5 °C) and NaOH·H 2 O (i.e., ∼69% NaOH, T m ≈ 62 °C). The melting point of a commercial 50% soda solution is near 15 °C . NaOH has a very high solubility in water (1115 g/L, which corresponds to 52.7% soda solution, at 25 °C).…”