Absorbance spectrophotometer , Physics

Assignment Help:

Absorbance spectrophotometer:

A schematic diagram of a simple instrument that is used to measure the absorption of visible light is shown in Figure below.

1116_absorbance spectrophotometer.png

When studying a compound in solution by spectrophotometry, you put it in a sample holder called a cuvette and place it in the spectrophotometer.  Light of a particular wavelength passes through the solution inside the cuvette and the amount of light transmitted (passed through the solution-Transmittance) or absorbed (Absorbance) by the solution is measured by a light meter. While a spectrophotometer can display measurements as either transmittance or absorbance, in biological applications we are usually interested in the absorbance of a given sample.

Because other compounds in a solution (or the solvent itself) may absorb the same wavelengths as the compound being analyzed, we compare the absorbance of our test solution to a reference blank.  Ideally, the reference blank should contain everything found in the sample solution except the substance you are trying to analyze or measure. For instance, in today's lab exercise you will be measuring the absorbance of a dye, bromphenol blue that was dissolved in water. The reference blank in this case would be water alone.

The amount of light transmitted through a solution is referred to as transmittance (T). The transmittance is defined as the ratio of the light energy transmitted through the sample (I) to the energy transmitted through the reference blank (I0). Since the compound being tested is not present in the reference blank, the transmittance of the reference blank is defined as 100%T.


Related Discussions:- Absorbance spectrophotometer

Time dilation, Time Dilation A description in which the phenomenon of t...

Time Dilation A description in which the phenomenon of time dilation from the special theory of associtively necessarily follows from the idea in which the speed of light is th

Explain radii of the two cross-sectional circular areas, Assume that two li...

Assume that two linked pistons are both cylindrical in shape. Show that the ratio of forces generated is directly proportional to the square of the radii of the two cross-sect

Phase angle, Two particles execute S.H.M of same amplitude and frequency ,a...

Two particles execute S.H.M of same amplitude and frequency ,along the same straight line from same mean position.They cross one another without collision,when going in opposite di

De-broglie wavelength, According to de-Broglie theory, the wavelength of de...

According to de-Broglie theory, the wavelength of de-Broglie wave is given by Where h = Plank's constant, m = Mass of the particle, v = Speed of the particle, E = Energy of

Perpendicular bisector , Determine the potential and field due to a short d...

Determine the potential and field due to a short dipole of dipole moment 5.0 X 10 -16 coulomb-cm at a point distant 1 cm from it. (a) on its axis (b) on its perpendicular bi

What is mass number if atomic number of d2 are 176 and 71, The radioactive ...

The radioactive isotope D decays according to the sequence If the mass number and atomic number of D2 are 176 and 71 respectively, what is (i) the mass number (ii) atomic

Calculate the total energy of a simple harmonic oscillator, Can you show ma...

Can you show mathematically that the total energy of a simple harmonic oscillator remains constant?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd