Search results
Results from the WOW.Com Content Network
Paraformaldehyde can be depolymerized to formaldehyde gas by dry heating [2] and to formaldehyde solution by water in the presence of a base, an acid or heat. The high purity formaldehyde solutions obtained in this way are used as a fixative for microscopy and histology. The resulting formaldehyde gas from dry heating paraformaldehyde is flammable.
A prominent example is the bacterial mesosome, which was thought to be an organelle in gram-positive bacteria in the 1970s, but was later shown by new techniques developed for electron microscopy to be simply an artifact of chemical fixation. [2] [3] Standardization of fixation and other tissue processing procedures takes this introduction of ...
A saturated water solution, of about 40% formaldehyde by volume or 37% by mass, is called "100% formalin". A small amount of stabilizer, such as methanol, is usually added to suppress oxidation and polymerization. A typical commercial-grade formalin may contain 10–12% methanol in addition to various metallic impurities.
This page contains tables of azeotrope data for various binary and ternary mixtures of solvents. The data include the composition of a mixture by weight (in binary azeotropes, when only one fraction is given, it is the fraction of the second component), the boiling point (b.p.) of a component, the boiling point of a mixture, and the specific gravity of the mixture.
C 5 H 6 O 2: furfuryl alcohol: 98-00-0 C 3 H 8 O 3: glycerol: 56-81-5 CH 3 OH: methanol: 67-56-1 CH 3 N(C 2 H 4 OH) 2: methyl diethanolamine: 105-59-9 CH 3 NC: methyl isocyanide: 593-75-9 C 5 H 9 NO: N-Methyl-2-pyrrolidone: 872-50-4 CH 3 CH 2 CH 2 OH: 1-Propanol: 71-23-8 CH 2 (CH 2 OH) 2: 1,3-Propanediol: 504-63-2 HOCH 2 CH 2 CH 2 CH 2 CH 2 OH ...
[1] [2] Common extractants may be arranged in increasing order of polarity according to the Hildebrand solubility parameter: ethyl acetate < acetone < ethanol < methanol < acetone:water (7:3) < ethanol:water (8:2) < methanol:water (8:2) < water. Solid-liquid extractions at laboratory scales can use Soxhlet extractors. A solid sample containing ...
Methanol for chemical use normally corresponds to Grade AA. In addition to water, typical impurities include acetone and ethanol (which are very difficult to separate by distillation). UV-vis spectroscopy is a convenient method for detecting aromatic impurities. Water content can be determined by the Karl-Fischer titration.
Water is the most common and well-studied polar solvent, but others exist, such as ethanol, methanol, acetone, acetonitrile, and dimethyl sulfoxide. Polar solvents are often found to have a high dielectric constant, although other solvent scales are also used to classify solvent polarity. Polar solvents can be used to dissolve inorganic or ...