Spectrophotometric Analysis of a Two-Component Mixture
Title: Spectrophotometric analysis of a two-component mixture
Aim: i. To prepare working standards of dichromate and permanganate ii. To measure the absorbance of the prepared working standards of dichromate and permanganate using a spectrophototometer iii. To determine the concentrations of permanganate in a mixture of unknown.
Abstract:
Working standards of dichromate and permanganate were prepared and absorbance for each found. This was done in order to plot a graph of absorbance versus concentration, from which the concentration of permanganate and dichromate in the unknown sample could be determined. Sulphuric acid was added to the standards in order to force the reaction to completion. Wavelengths of 430 nm and 525 nm were chosen as dichromate absorbs best at 430 nm, while permanganate absorbs best at 525 nm. The concentrations of dichromate and permanganate in the unknown sample were 0.0122 M and - 1.94 x 10-3 M respectively. The negative value obtained for the permanganate ion concentration showed that the concentration was extremely low.
Introduction:
Spectrophotometry is the measurement of how different wavelengths of light are absorbed. Using a spectrophotometer to determine how much of a particular wavelength of light is absorbed by a specimen can yield important insights into its characteristics apart from its mass, crystalline structure and other features. Spectrophotometers are useful because of the relation of intensity of colour in a sample and its relation to the amount of solute within the sample.
A UV-Visible spectrophotometer makes use of the transmission of light through a solution to determine the concentration of a solute within the solution. A spectrophotometer consists of two instruments, namely a spectrometer for producing light of any selected colour (wavelength), and a photometer for measuring the intensity of light.
The visible light can be divided into six principal colours. Therefore, a
Aim: i. To prepare working standards of dichromate and permanganate ii. To measure the absorbance of the prepared working standards of dichromate and permanganate using a spectrophototometer iii. To determine the concentrations of permanganate in a mixture of unknown.
Abstract:
Working standards of dichromate and permanganate were prepared and absorbance for each found. This was done in order to plot a graph of absorbance versus concentration, from which the concentration of permanganate and dichromate in the unknown sample could be determined. Sulphuric acid was added to the standards in order to force the reaction to completion. Wavelengths of 430 nm and 525 nm were chosen as dichromate absorbs best at 430 nm, while permanganate absorbs best at 525 nm. The concentrations of dichromate and permanganate in the unknown sample were 0.0122 M and - 1.94 x 10-3 M respectively. The negative value obtained for the permanganate ion concentration showed that the concentration was extremely low.
Introduction:
Spectrophotometry is the measurement of how different wavelengths of light are absorbed. Using a spectrophotometer to determine how much of a particular wavelength of light is absorbed by a specimen can yield important insights into its characteristics apart from its mass, crystalline structure and other features. Spectrophotometers are useful because of the relation of intensity of colour in a sample and its relation to the amount of solute within the sample.
A UV-Visible spectrophotometer makes use of the transmission of light through a solution to determine the concentration of a solute within the solution. A spectrophotometer consists of two instruments, namely a spectrometer for producing light of any selected colour (wavelength), and a photometer for measuring the intensity of light.
The visible light can be divided into six principal colours. Therefore, a
References: Crouch, S., Holler, F., Skoog, D. & West, D. (8th ed.) (2004). Fundamentals of Analytical Chemistry. (pp. 786-787, 796-797). Nelson Education Ltd. • Starna Cells. (n.d.). Potassium Dichromate Reference: For assessing the absorbance scale of your UV spectrophotometer. Retrieved March 17, 2011 from file:///F:/Analytical%20Chemistry/PDC.html