Analytical Techniques

Which technique would be most appropriate to indicate the three-dimensional structure of a molecule?

• X-ray crystallography

• mass spectroscopy

• chromatography

• infrared spectroscopy

Which of the following statements about the electromagnetic spectrum is false?

• Electromagnetic waves with a longer wavelength have a lower frequency.

• All aspects of the spectrum travel at the same speed.

• X-rays have a higher frequency than visible light.

• All aspects of the spectrum have the same energy.

Which of the following does not affect the amount of deflection during mass spectroscopy?

• mass of the particle

• strength of the magnetic field

• charge of the particle

• atoms that contribute to the mass of the particle

Which of the following is not detected during mass spectroscopy?

• positive ions

• a cation with a charge of +

• a radical

• a cation with a charge of +1

In X-ray crystallography the crystals are usually produced by:

• rapidly cooling supersaturated solutions.

• slowly cooling unsaturated solutions.

• rapidly cooling unsaturated solutions.

• slowly cooling supersaturated solutions.

X-rays may be produced when electrons move to an energy level that is:

• slightly further away from the nucleus.

• significantly further away from the nucleus.

• slightly closer to the nucleus.

• significantly closer to the nucleus.

X-ray crystallography is based on the scattering of:

• light by electrons.

• X-rays by protons.

• X-rays by electrons.

• light by protons.

During infrared spectroscopy the frequencies absorbed depend on:

• whether the bond is single, double or triple.

• the atom’s size.

• the bond length.

• all of the above

What characteristic of the light absorbed is compared between known and unknown samples in UV-visible spectroscopy?

• frequency

• energy

• wavelength

• colour

Carbon dating of fossils is based on the ratio of carbon-12 to carbon-14. The technique used is:

• X-ray crystallography.

• mass spectroscopy.

• chromatography

• infrared spectroscopy.