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

Explain squirrel cage induction motors, Mines Flame proof squirrel cage...

Mines Flame proof squirrel cage induction motors are used in coal mine.

Passing lane velocity vs time graph, Passing Lane velocity vs time graph ...

Passing Lane velocity vs time graph Suppose the two cars below. The blue car begins ahead of" the red car. The red car actually begins off the screen.) Because the red car is

Electric field and the associated magnetic field, What the angles among the...

What the angles among the direction are of travel of light the electric field and the associated magnetic field? Answer: The magnetic field created by a changing electric

9th, what is dynamics

what is dynamics

#titleoptics.., a small object is 10cm in front of a plane mirror if you st...

a small object is 10cm in front of a plane mirror if you stand behind the object 30cm from it and look at its image for what distance must you focus your eyes

Determine the velocity of the mass, A 10 kilogram mass rests on a horizonta...

A 10 kilogram mass rests on a horizontal frictionless surface. A horizontal force of 5 Newtons is applied to the mass.  After the force has been applied for 1 second, the velocity

Illustrate how is nuclear fission different from fusion, Q. Illustrate how ...

Q. Illustrate how is nuclear fission different from nuclear fusion? Answer:- Nuclear fusion is taking two different atoms as well as combining them in to one atom while nu

Explain earth’s magnetic field , As per the most established theory it is b...

As per the most established theory it is because of the rotation of the earth where by the several charged ions there in the molten state in the core of the earth rotate and consti

Illustrates principle of transmission electron microscope, Illustrates the ...

Illustrates the principle of transmission electron microscope? Principle of Transmission Electron Microscope The electron microscopes are worked onto the basis of, while a b

Explain static capacitors, Static Capacitors: The power factor can be impr...

Static Capacitors: The power factor can be improved by between capacitors in parallel with the equipment operating at lagging power factor. The capacitor draws a leading current a

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