003 UV Vis

Question 1

an analytical technique that determines the conjugated p electron system present in the compound

Answer 1

Ultraviolet and visible spectroscopy (UV/Vis)

Question 2

A technique used to determine the ff.
✓ Functional groups present in the compound
✓ Size and formula of the compound
✓ Carbon-hydrogen framework of the compound

Answer 2

Infrared spectroscopy (IR)
Mass spectrometry (MS)
Nuclear magnetic resonance spectroscopy (NMR)

Question 3

have just the right energy to cause an electronic
transition of an electron from one orbital to another of higher
energy

Answer 3

UV/Vis light

Question 4

ultraviolet wavelengths :
visible light wavelengths :

Answer 4

180 - 400 nm
400 - 780 nm

Question 5

normal electronic
configuration of a
molecule

Answer 5

ground state

Question 6

Just a note!

only organic compounds
with π electrons can
produce UV Vis spectra

Answer 6

NA

Question 7

part of a molecule
that absorbs UV or visible light

Answer 7

chromophore

Question 8

UV A lowest-energy UV light
UV B
UV C

Answer 8

315 to 400 nm
290 to 315 nm
180 to 290 nm

Question 9

Just a note!

Conjugation raises the energy of the HOMO and lowers the energy of the LUMO

Answer 9

NA

Question 10

A substituent that when attached to a
chromophore, alters the λmax and the intensity of the absorption (usually increasing both) and give example

Answer 10

Auxochromes
OH and NH2

Question 11

class of highly conjugated compounds responsible for the red, purple, and
blue colors of many flowers, fruits, and vegetables

Answer 11

Anthocyanins