Pharmaceutical Analysis Quiz

Select the wavelength range corresponding to UV-visible region

• 400-800 nm

• 200-800 nm

• 25 μm-2.5 μm

• 2.5 μm – 1mm

If the above compound was completely reduced, what will be the possible transitions it can undergo?

• n→p*

• s→s*

• p→p*

• n→s*, s→s*

In which region of the electromagnetic spectrum does an absorption at 600 nm come

• Near UV

• Infrared

• Vaccum UV

• Visible

A solution of 0.001 mol dm–3 NiSO4 is placed in an optical cell of pathlength 1 cm, and the absorption spectrum is recorded. The absorptions have characteristic λmax and εmax values. What are the correct units of εmax?

• cm mol dm–3

• Dm3 mol–1 cm–1

• mol dm–3 cm–1

• cm dm3 mol–1

In which region of the electromagnetic spectrum does an absorption at 177 nm come?

• Infrared

• Near UV

• Visible

• Vaccum UV

What does the notation σ*←n mean?

• Absorption; transition from a non-bonding MO to σ* MO.

• Absorption; transition from a quantum level n to σ* MO

• Emission; transition from a quantum level n to σ* MO.

• Emission; transition from a non-bonding MO to σ* MO

How do values of λmax for the π*←π transitions vary among a series of conjugated polyenes

• Values vary very little

• Values shift to shorter wavelength as the number of C=C double bonds increases

• Values shift to longer wavelength as the number of C=C double bonds increases.

• Values vary but in no particular pattern.

What is a red shift?

• The shifting of an absorption to higher energy.

• The shifting of an absorption to shorter wavelength

• The shifting of an absorption towards the blue end of the spectrum.

• The shifting of an absorption to lower energy.

What is a chromophore?

• A group of atoms in a compound responsible for the absorption of electromagnetic radiation.

• A group of atoms in a coloured compound.

• A group of atoms in a compound responsible for electromagnetic radiation.

• A coloured compound.

Which of the following is the principal chromophore in an azo-dye?

• N≡N

• C=N

• N=N

• C≡N