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Showing posts from December, 2019


Polarimeter   Substance are optically in the sense that the rotate on incident plane or polarized light so that the transmitted light energy at a measurable angle to the plane of the incident light. Plane polarized light:  According to wave theory of light, an ordinary ray of light is considered to be vibrating to all planes at right angle to the direction of its propagation.If this ordinary ray of light is pass through a Nicol prism the emergent ray has its vibrations only in one plane.This light having wave motion in only one plane is known as plane polarized light. Optical Activity: When certain organic liquid solution (like sugar) or quartz crystal are placed in the path of plane polarized light, the plane of polarization is rotated.The property by virtue of which the plane of polarization of light is rotated is called optical activity and the substances possessing this property are said to be optically active. Substances which rotate the plane of polarized lig

Karl Fischer (K.F.)

Karl Fischer (K.F.) Karl Fischer (KF) titration is water determination techniques which is industrial scientists. It is performed by volumetric or coulometric measurement techniques. Principles of Karl Fischer titration: The KF reaction is based upon an early reaction called the Bunsen reaction, in which sulfur dioxide is oxidized by iodine with the consumption of water during this oxidation. German scientist Karl Fischer published a method in  a year 1935 for determination of water content in samples. This was a titrimetric method based on Bunsen re action used for determination of sulfur dioxide in aqueous solutions. The original reaction is as below: SO 2 + I 2 + 2H 2 O → H 2 SO 4 + 2HI The KF titration reaction currently accepted is as follows, and was reached by several advances in understanding the mechanism of the reaction and modification of the original reagent: The titration reaction is said to reach its endpoint once the iodine stops reacting with the

Ultraviolet Visible Spectroscopy (U.V.)

Ultraviolet Visible Spectroscopy (U.V.) What is UV spectroscopy :   UV spectroscopy is the measurement of the attenuation of the beam of light passing through a sample or after reflection from the sample surface. Ultraviolet light:   Wavelength between 190 nm to 400 nm        Visible light:   Wavelength between 400 nm to 800 nm   Principal of UV:   UV spectroscopy is absorption spectroscopy. It is based upon the phenomenon of electronic excitation so when UV radiation are passed through the sample the atoms or molecules absorbs the energy and moves from ground state to the excited state. If it occurs the residual radiation. It is passed through a prism here is a spectrum with gap in it and it is called an absorption spectrum. The excitation is detected by the detector amplified and recorded. Image Source-Google | Image by - QC/QA Methodology Lambert's  beer’s law: When a monochromatic light pass through in a transparent medium the rate of intensity is decreases