Spectroscopy

Question 0

Why are different frequencies of colour used for different solutions in a Colorimetry experiment?

Answer 0

Different substances absorb different colours. Certain frequencies of colour are used to maximise results of finding the amount of light passing through a solution.

Question 1

What is a flame test and what does it show?

Answer 1

The colour given off when a substance is sprayed into a flame indicates the metal type and is an emission spectra.

Question 2

What does Mass Spectrometry do?

Answer 2

Converts molecules and atoms into positive ions.

Question 3

What is a “parent ion”?

Answer 3

The largest and/or heaviest ion of a number of ions tested in Mass Spectrometry.

Question 4

What does AAS stand for and is useful for?

Answer 4

Atomic Absorption Spectroscopy is used to identify metallic elements.

Question 5

Why are different wavelengths of light used?

Answer 5

To identify certain metals.

Question 6

What is IR and how is it useful?

Answer 6

Infra-Red Spectroscopy identifies certain functional groups. E.g. CH3, OH or COOH.

Question 7

How is IR able to identify double and triple bonds?

Answer 7

Covalent bonds:
- stretch
- bend
- vibrate
Since atoms experience these movements, they have an amount of energy. The type of bond can be found from the amount of energy (absorbed from the IR region).

Question 8

What does a IR spectrum table identify?

Answer 8

Either the functional groups (above 1000/cm) or molecules (usually below 1000/cm).

Question 9

What do the number of peaks in an IR spectrum graph imply?

Answer 9

The more types of atoms in a molecule.

Question 10

What does the chemical shift in NMR show?

Answer 10

The chemical shift in Nuclear Magnetic Resonance indicate ppm.

Question 11

What does NMR’s spectrum show?

Answer 11

The peaks in Nuclear Magnetic Resonance’s spectrum indicates the species.
The number of peaks indicates how many Hydrogens are present.