Question

What part of the spectra out provides information about the identity of the compound?

Molar Absorptivity, Transmission , Absorbance, Wavelength

What part of the spectra out provides information about the quantity of the compound?

Molar Absorptivity, Transmission , Absorbance, Wavelength

How is the measured quantity, transmittance, related to the calculated quantity, absorbance?

Absorbance = 1/transmittance, Absorbance = e^(transmittance) , Absorbance = transmittance, Absorbance = -log(transmittance)

How is absorbance related to concentration (the symbol α means proportional to)?

Absorbance α concentration, Absorbance α -log(concentration) , Absorbance α e^( concentration), Absorbance α 1/ concentration

Answer 1

1. What part of the spectra out provides information about the identity of the compound?

Answer: Wavelength

Because for a particular chemical species there will be a particular λmax by which one can identify a compound.

Molar absorptivity tells that how a chemical species attenuates lights at a particular wavelength.

Transmittance tells about how much of light is transmitted after passing through a chemical species.

Absorbance tells about the amount of light absorbed by a chemical species.

2. What part of the spectra out provides information about the quantity of the compound?

Answer: Molar absorptivity

Molar absorptivity tells that how a chemical species attenuates lights at a particular wavelength.

3. How is the measured quantity, transmittance, related to the calculated quantity, absorbance?

Answer: Absorbance = -log(transmittance)

A= -log(T)

T= Transmittance T = P (power of monochromatic light initial) / P0 (Power of monochromatic light after passing through solution) A= Absorbance

A =logP0/P A =log(1/T) A= -log T 4. How is absorbance related to concentration (the symbol α means proportional to)? Answer: Absorbance α concentration A= CL ----Beer Lambert's Law =molar absorptivity coefficient C= concentration of solution L = Path length And hence we can say that A is directly proportional to the concentration of the solution.