Instrumentation in organic chemistry

Question 1

What is chromatography?

Answer 1

Chromatography is a separation technique is which a moblie phase carries a mixture of components through a stationary phase
The componests in the mixtire are selectively adbsorbed onto the stationary phase and pass through at different times

Question 2

What is a mixture

Answer 2

substance consisting of two or more substances migled together but not chemically combined

Question 3

Name the thee types of chromotography

Answer 3

paper chromatography/
Gas chromatography/
High performance liquid chromotography (HPLC)

Question 4

Describe the procedure

Paper chromatography

Answer 4

Using a dropper, place a drop of ink or indicator 2cm up from the bottom of the chromotography paper on a pencil line drawn.
Place the chromatography paper into a beaker with 1cm of suitable eluent
leave for 1 hour

Question 5

Describe the result

Paper chromatography

Answer 5

As the eluent moblie phase moves up the chromotography paper, each component colour in the ink is selectively adsorbed and appears in the chromotography paper stationary at differnt times

Question 6

what is the mobile phase and the stationary phase

Paper chromatography

Answer 6

Moblie phase : liquid eluent/ solvent
Stationary phase: chromatography paper

Question 7

Name a suitable solvent for a soluable mixture and an insoluble solvent

Paper chromatography

Answer 7

Water
(Insoluble - methanol)

Question 8

Why is the line drawn on to the chromotograpy in pencil

Paper chromatography

Answer 8

avoids contamination with other types of ink

Question 9

Where should the pencil line be drawn on the chromotography paper,explain why this is important

Paper chromatography

Answer 9

2cm up the chromotopraphy paper, this avoids the solvent dissolving the ink before it moves up the paper

Question 10

Describe the principle of atomic absorbtion spectrometry

Answer 10

Different elements can be identifyed by the wavelenghts/ frequencies of light they absorb

Question 11

describe the principle of mass spectrometry

Answer 11

Isotopes are converted into postive ions and are separated according to their mass by being accelerated by a magnetic field

Question 12

Give three uses of a mass spectrometer

Answer 12

Identifies the presence of isotopes
measures the relative abunadances of each isotope and calculate the relative atomic masses and relative molecular masses.
Can detect banned drugs taken by athlete

Question 13

Describe the principle of Infra-Red spectrometry

Answer 13

Different functional groups of organic molecules absorb different frequencies of infra-red radiation and can be idetified.
It can identify organic compounds

Question 14

Name a low energy electromagnetic radiation

Answer 14

Infra-red

Question 15

Name uses for IR speactrometry

Answer 15

Identification of drugs and plastics
breathalyser tests

Question 16

Describe the principle of Ultra-Violet (UV spectrometry)

Answer 16

The amount og ultra radiation absorbed by a substance is directly porportional to the concetration of the substance
Therefore Uv spectrometry can be used to dertime concentrations of organic compound

Question 17

Name a high energy electrostatic radiation

Answer 17

Uv radiation

Question 18

Give two uses of UV specrometry

Answer 18

test presence of drugs and measure their concentrations, Detect pigmants and measure their concentrations