unit 5 spectroscopy technique

The electric and magnetic field of an electromagnetic wave are

• in opposite phase and perpendicular to each other

• in opposite phase and parallel to each other

• in phase and perpendicular to each other

• in phase and parallel to each other.

Select the wavelength range corresponding to UV-visible region

• 400-800 nm

• 200-800 nm

• 25 μm-2.5 μm

• 2.5 μm – 1mm

The types of transitions possible in UV-visible region for a compound with molecular formula C ₂H ₄O are

• P,Q,R

• Q,R

• P,S

• P,Q,R,S

The possible transitions for water molecule in UV-visible region are

• σ →σ ^*

• n→π ^*, π→π ^*

• σ→σ ^*, n→π *

• n → σ^*

Electronic transition possible for methane CH₄

• σ →σ ^*

• π→π *

• n → σ^*

• n→π *

Increasing order of wavelength is

• X-ray, UV, IR, Microwave

• Microwave, IR, UV, X-ray

• UV, IR, X-ray, Microwave

• Microwave, UV, IR, X-ray

The value to TMS proton in 𝛿 scale is

• 10

• 0

• not predictable

• -10

The fingerprint region in IR spectra ranges from

• 1500-700 cm-1

• 2260-2190 cm-1

• 1950-1550 cm-1

• none of the above

Radiation source for visible spectrophotometer is

• Tungsten filament lamp

• Nersut glower

• xenon discharge lamp

• heated nichrome wire

In NMR spectroscopy, the radiation used for nuclear excitation is

• Microwaves

• IR

• Radio waves

• UV