Chromophore, transitions, auxochromes

How many electronic transitions are possible in UV-Visible spectroscopy?

• 3

• 4

• 5

• 6

UV-Visible region is

• 100-900 nm

• 200-500 nm

• 100-800 nm

• 200-800 nm

Which among the following impart colour to the organic compound?

• Auxochrome

• Chromophore

• Chromone

• Auxochromone

Which one is the forbidden transition?

• sigma to sigma *

• pi to pi*

• n to sigma*

• n to pi*

Which transition requires low energy?

• sigma to sigma *

• pi to pi*

• n to sigma*

• n to pi*

Which transition requires higher energy?

• sigma to sigma *

• pi to pi*

• n to sigma*

• n to pi*

Shift of an absorption maximum to longer wavelength is called

• Hyperchromic shift

• Hypsochromic shift

• Bathochromic shift

• Hypochromic shift

What are auxochromes?

• Groups of atoms that cause a shift in the absorption spectrum of a compound

• Categories of programming languages

• Species of exotic flowers

• Types of musical instruments

How do auxochromes affect the color of a compound?

• They have no effect on the color of the compound.

• They cause the compound to become colorless.

• They extend the conjugated system and shift the absorption spectrum.

• They decrease the conjugated system and shift the absorption spectrum.

Explain how auxochromes influence the color of dyes.

• Auxochromes have no effect on the color of dyes

• Auxochromes change the physical state of the dye

• Auxochromes decrease the conjugation of the dye molecule

• Auxochromes extend the conjugation of the dye molecule, affecting the wavelength of light absorbed and reflected.