(A1) Determining Molar Absorptivity: A Serial Dilution of Benzophenone a) Weigh
ID: 476407 • Letter: #
Question
(A1) Determining Molar Absorptivity: A Serial Dilution of Benzophenone a) Weigh 0.125 g of benzophenone into a 50.00 mL volumetric flask. Record the mass that you weigh to the nearest 0.001 g. Ensure that the volumetric flask is dry before adding the benzophenone. Alternatively, you may rinse the flask 2-3 times with ethanol before the addition of benzophenone b) Add ~20-25 mL of ethanol and swirl the flask until the benzophenone is dissolved. c) Fill the flask to the 50.00 mL line with ethanol. Use a pipet to add the last few drops. Note that the bottom of the meniscus should coincide with the 50.00 mL line. If you add too much solvent, you will need to empty the flask, rinse with solvent and start over. Cap the flask, mix well, and label a Solution A.Explanation / Answer
5.
The electronic transitions of the electrons in the molecule (benzophenone) are due the absorption of the radiation in the visible-ultraviolet region of the electromagnetic spectrum.Solution A-C are colorless because the electronic tranisition from the excited state of the molecule to the ground state do not fall in the visible region of the electromagnetic spectum. As the wavlenght of absorbption is 252 nm which corresponds to the UV region of the electromagnetic spectrum.
6.
The most frequent electronic transitions during absorption of UV or visible radiation is to *, n to * and n to * .
The electrons which are involved in the electronic transitions of benzophenone molecule is due to:
1. Non bonding outer shell electrons (n electrons) O present in carbonyl group of benzophenone.
2. The electrons in the pi orbital which are present in benzene rings of the benzophenone.
Chromophore: An atom or group of atoms/ functional group whose presence in the molecule is responsible for the colour of that compound. The chromophore in this molecule are the two benzene rings attached to the carbonyl group.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.