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Indicator: A substance that changes color in response to a chemical change. An acid–base indicator (e.g., phenolphthalein) changes color depending on the pH. Redox indicators are also used. A drop of indicator solution is added to the titration at the beginning; the endpoint has been reached when the color changes.
A vacutainer blood collection tube is a sterile glass or plastic test tube with a colored rubber stopper creating a vacuum seal inside of the tube, facilitating the drawing of a predetermined volume of liquid. Vacutainer tubes may contain additives designed to stabilize and preserve the specimen prior to analytical testing.
The color can be easily observed in a glass of tap-water placed against a pure white background, in daylight. The principal absorption bands responsible for the color are overtones of the O–H stretching vibrations. The apparent intensity of the color increases with the depth of the water column, following Beer's law. This also applies, for ...
The equipment required is a colorimeter, some cuvettes and a suitable color reagent. The process may be automated, e.g. by the use of an AutoAnalyzer or by flow injection analysis . Recently, colorimetric analyses developed for colorimeters have been adapted for use with plate readers to speed up analysis and reduce the waste stream.
Toluene (/ ˈ t ɒ l. j u iː n /), also known as toluol (/ ˈ t ɒ l. j u. ɒ l,-ɔː l,-oʊ l /), is a substituted aromatic hydrocarbon [15] with the chemical formula C 6 H 5 CH 3, often abbreviated as PhCH 3, where Ph stands for the phenyl group.
Chemistry is the scientific study of the properties and behavior of matter. [1] It is a physical science within the natural sciences that studies the chemical elements that make up matter and compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during reactions with other substances.
Viscosity is a measure of a fluid's rate-dependent resistance to a change in shape or to movement of its neighboring portions relative to one another. [1] For liquids, it corresponds to the informal concept of thickness; for example, syrup has a higher viscosity than water. [2]
Iridescence is an optical phenomenon of surfaces in which hue changes with the angle of observation and the angle of illumination. [ 2 ] [ 3 ] It is often caused by multiple reflections from two or more semi-transparent surfaces in which phase shift and interference of the reflections modulates the incidental light , by amplifying or ...