Miscellaneous Instrumentation Questions

 1) A more recent development in liquid chromatography is ___________________.

A) Counter Current Chromatography.

B) Reversed Phase Chromatography.

C) Ion Exchange Chromatography.

D) Size Exclusion Chromatography.

Answer: A) Counter Current Chromatography.

Explanation: A more recent development in liquid-liquid chromatography is Counter current Chromatography which entirely eliminates the use of a solid matrix support. The theory of CCD was described in the 1930s by Randall and Longtin. Archer Martin and Richard Laurence Millington Synge developed the methodology further during the 1940s. Finally, Lyman C. Craig introduced the Craig counter current distribution apparatus in 1944 which made CCD practical for laboratory work.

2) The transition zone for Raman spectra is __________

A) Between electronic levels

B) Between vibrational and rotational levels

C) Between magnetic levels of nuclei

D) Between magnetic levels of unpaired electrons

Answer: B) Between vibrational and rotational levels

Explanation: Raman spectra have a transition zone between vibrational and rotational levels. Raman spectroscopy is a spectroscopic technique for observing low-frequency vibrational, rotational, and other modes in a system.

3) Match the Following

Chromatographic Instrument Scientist & Year

1) Gas Chromatography.                     A) Tswett in 1903

2) Ion Exchange Chromatography   B) Starkenstein in 1910

3) Adsorption Chromatography       C) Martin and James in 1952

4) Affinity Chromatography              D) Small, Stevens and Bauman in 1975

a) 1-D, 2-A, 3-B, 4-C

b) 1-C, 2-D, 3-A, 4-B

c) 1-D, 2-C, 3-A, 4-B

d) 1-C, 2-B, 3-D, 4-A

Answer: B) 1-C, 2-D, 3-A, 4-B

Explanation: Gas Chromatography was Invented by Martin and james in 1952.

Ion Exchange Chromatography was Invented by Small, Stevens and Bauman in 1975.

Adsorption Chromatography was Invented by Tswett in 1903. Affinity Chromatography was Invented by Starkenstein in 1910.

4) Select the incorrect Statement form the following options

A) Emission Spectrum results when an electron in an atom undergoes a transition from excited state to the ground state.

B) In the emission spectrum, transition takes place with the emission of a photon of energy hv.

C) In the emission spectrum, transition takes place with the absorption of a photon of energy hv.

D) All of the Above.

Answer: C) In the emission spectrum, transition takes place with the absorption of a photon of energy hv.

Explanation: In the emission spectrum, transition takes place with the emission of a photon of energy hv. All other options are correct. Emission spectrum results when an electron in an atom undergoes a transition from excited state to the ground state.

5) The Term eddy diffusion is used in which of the following analytical techniques.

A) Neutron Activation Energy

B) Spectroscopy

C) Chromatography

D) Colorimetry

Answer: C) Chromatography

Explanation: Chromatographic peaks are generally broadened by three kinetically controlled processes, eddy diffusion, longitudinal diffusion, and non-equilibrium mass transfer. 1) Eddy diffusion: Zone broadening from eddy diffusion is the result of the multitude of pathways by which a molecule can find its way through a packed column. 2) Longitudinal diffusion: Longitudinal diffusion results from the tendency of molecules to migrate from the concentrated centre part of a band towards more dilute regions on either side. 3) Non-equilibrium mass transfer: Chromatographic bands are also broadened because the flow of the mobile phase is ordinarily so rapid that true equilibrium between phases cannot be realized.

6) Which of the following is a limitation of the Lamberts-Beer’s law?

A) Scattering of light due to particles

B) Fluorescence of sample

C) Non-monochromatic radiation

D) All of the Above

Answer: D) All of the above

Explanation: Scattering of light due to particles, fluorescence of the sample and non-monochromatic radiation are the limitations of Lambert-Beer’s law. It relates the attenuation of light to the properties of the material through which the light is traveling.

7) Inductively coupled plasma emission spectrometry has been successfully applied in the identification and characterization of

A) Glass fragments and Paint Chips.

B) Paint chips and Soil Comparisons.

C) Glass fragments and Mutilated Bullets.

D) Mutilated Bullets and Paint chips.

Answer: C) Glass fragments and Mutilated Bullets.

Explanation: Inductively coupled plasma emission spectroscopy (ICP-ES), is an analytical technique used for the detection of chemical elements. It is a type of emission spectroscopy that uses the inductively coupled plasma to produce excited atoms and ions that emit electromagnetic radiation at wavelengths characteristic of a particular element. It is used in forensic science to analysed Glass fragments and mutilated bullets also its used to determination of metals in wine, arsenic in food and trace elements bound to proteins

8) The greater the polarity of a bond the _______________ its IR absorption.

A) Weaker

B) Stronger

C) More charged

D) Smaller the wavenumber

Answer: B) Stronger

Explanation: For a bond to absorb in IR, there must be a change in the dipole moment during the vibration. If a bond is non-polar due to symmetry, IR light will not be absorbed and the vibration is said to be IR inactive. A more polar bond will have a stronger absorption than a less polar bond.

9) On which law Gas-Liquid Chromatography is based?

A) Henry’s Law

B) Piobert’s Law

C) Beer’s Law

D) Newtons Law

Answer: A) Henry’s Law

Explanation: According to Henry’s law, the partition of an analyte over the gas phase and liquid phase is the ratio of mole fractions in the vapor phase and the liquid phase.

10) The fingerprint region of IR spectrum can be subdivided in the following spectrum except

A) 1500-1350 cm-1

B) 1350-1000 cm-1

C) Below 1000 cm-1

D) Below 500 cm-1

Answer: D) Below 500 cm-1

Explanation: The fingerprint region ranges from 1450-500cm-1 and this region has an almost unique spectrum for a compound and that is why they are called the fingerprint region.