UV-Visible Spectroscopy

UV radiation extends from

• 10 nm to 400 nm

• 100 nm to 400 nm

• 50 nm to 400 nm

• 150 nm to 400 nm

Energy and Wavelength are ---------- to each other.

• Directly proportional

• Inversely proportional

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

• 3

• 4

• 5

• 6

UV spectrum is a plot of ------------ versus absorption intensity

• frequency

• wavelength

• wavenumber

• energy

UV spectrum is sharp say yes or no

• yes

• no

Shift of an absorption maximum to longer wavelength is called

• Hyperchromic shift

• Hypsochromic shift

• Bathochromic shift

• Hypochromic shift

Which transition requires higher energy?

• 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 one is the forbidden transition?

• sigma to sigma *

• pi to pi*

• n to sigma*

• n to pi*

What is the absorption maximum value of 1,3-butadiene?

• 215 nm

• 216 nm

• 217 nm

• 219 nm