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Sodium hydroxide

anhydrous, free-flowing, pellets, Redi-Dri, ACS reagent, ≥97%

‘Caustic soda’
Linear Formula:
CAS Number:
Molecular Weight:
EC Number:
MDL number:
PubChem Substance ID:

Quality Level


ACS reagent

vapor density

>1 (vs air)

vapor pressure

<18 mmHg ( 20 °C)
3 mmHg ( 37 °C)

product line









≤0.001% N compounds
≤0.02% NH4OH ppt.
≤1.0% Na2CO3


318 °C (lit.)


water: soluble 1260 g/L at 20 °C


2.13 g/cm3

anion traces

chloride (Cl-): ≤0.005%
phosphate (PO43-): ≤0.001%
sulfate (SO42-): ≤0.003%

cation traces

Fe: ≤0.001%
Hg: ≤0.1 ppm
K: ≤0.02%
Ni: ≤0.001%
heavy metals (as Ag): ≤0.002%

SMILES string




InChI key


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General description

Sodium hydroxide (NaOH) also known as caustic soda is a water soluble inorganic base with a wide range of industrial application such as titration, dissolution testing and in impinger to remove acidic gases. It participates in the oxidation of glycerol catalyzed by Au/charcoal or Au/graphite. It participates in solvent-free aldol condensation reaction.


Sodium hydroxide (NaOH) was used in the following processes:
  • Preparation of sodium 3,3′-bis(sulfonato)-4,4′-bis(chloroacetamido)azobenzene (BSBCA) that is utilized in protein cross-linking techniques.
  • Preparation of electrolyte solution to study the effect of electrolyte composition on the conversion of CO2 to CO by electrochemical reduction.
  • Preparation of CSK (cytoskeleton) buffer for the three-dimensional (3D) slide method of preserving the 3D chromatin structure of testicular germ cells.
  • Synthesis of ZSMs (zeolite socony mobils).

Sodium hydroxide may be employed for the deterimination of specific surface area of colloidal silica, via titration. It may be employed for the direct oxidation of sodium borohydride, which was investigated by cyclic and linear voltammetry, chronoamperometry and chronopotentiometry. It may be used to prepare citrate buffer and borate buffer.

It may be used in the synthesis of :
  • alkylaryl amidosulfobetaines
  • (3 -[4-teroctylphenoxyethoxyethoxyethyl] dimethylammonio propane sulfonate (XOSB)
  • trisulfobetaines (TriSBn)

Sodium hydroxide may be used as a base in titration methods, dissolution testing, for adjusting pH and in the impinger to remove acidic gases.

It may be used in the following processes:
  • Conversion of glycerol to glyceric acid in the presence of gold catalyst.
  • Palladium-catalyzed cross-coupling reaction between vinylalkoxysilanes and aryl bromides or chlorides to form styrenes.


1, 2.5 kg in poly bottle
500 g in poly bottle

Features and Benefits

  • Increased efficiency – Eliminate time and effort of loosening hardened powders
  • Safety – Avoid risks of using tools of force to break up clumps
  • Economy – Faster preparation and solvation increase productivity and reduce costs
  • Assured quality – Excellent, expert-tested quality with no anti-caking agents
  • Flexible volumes – Available from research amounts to scale-up quantities

Legal Information

Redi-Dri is a trademark of Sigma-Aldrich Co. LLC



Signal Word


Hazard Statements

Hazard Classifications

Eye Dam. 1 - Met. Corr. 1 - Skin Corr. 1A

Storage Class Code

8B - Non-combustible, corrosive hazardous materials



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Enter Lot Number to search for Certificate of Analysis (COA).

Certificate of Origin

Enter Lot Number to search for Certificate of Origin (COO).

Bilal Çakir et al.
Plant foods for human nutrition (Dordrecht, Netherlands), 74(3), 414-420 (2019-07-07)
The amount of cold press oil manufacture is globally rising, which in turn leads to the accumulation of deoiled plant seeds at significant quantities and consequent manufacture of plant protein products. In this study, we made an attempt to analyze
Hanyu Zhang et al.
Nanoscale, 12(15), 8344-8354 (2020-04-03)
By understanding how the environmental composition impacts the optoelectronic properties of transition metal dichalcogenide monolayers, we demonstrate that simple photoluminescence (PL) measurements of tungsten disulfide (WS2) monolayers can differentiate relative humidity environments. In this paper, we examine the PL and
Debonil Maity et al.
Soft matter, 15(12), 2617-2626 (2019-02-28)
Extracellular matrices in animal tissue are hydrogels mostly made of collagen. In these matrices, collagen fibers are hierarchically assembled and cross-linked to form a porous and elastic material, through which migrating cells can move by either pushing through open matrix
Ruobing Bai et al.
Macromolecular rapid communications, 40(8), e1800883-e1800883 (2019-02-12)
New applications of hydrogels draw growing attention to the development of tough hydrogels. Most tough hydrogels are designed through incorporating large energy dissipation from breaking sacrificial bonds. However, these hydrogels still fracture under prolonged cyclic loads with the presence of
Seetharam Deepa et al.
Nanotoxicology, 13(2), 240-257 (2019-01-22)
The present study analyzed the effects of zinc oxide nanoparticles (ZnO-NPs) and zinc sulfate (ZnSO4) in the testis of six-month-old common carp Cyprinus carpio exposed to three different doses, viz., 10, 50, and 100 μg/L for 21 days. Characterization of ZnO-NPs was

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