Post Test Gas Chromatography

Two or more substances that are mixed together but not chemically combined is a ___

• compound
• mixture
• keratin
• chromatography

A low retention time indicates

• a high affinity to the mobile phase
• a low affinity to the stationary phase
• a high solubility in the mobile phase
• all of the above

The substance in the mixture that has the greatest affinity for the stationary phase will travel

• fastest
• slowest

The retention time is used

• to zero the chromatography scale

• to identify unknown compounds in a sample

• to retain solvent

• as a starting tool for chromatography

What is chromatography?

• The process by which particles move from a region of higher concentration to lower concentration

• The process by which water is purified

• The method through which solutes are separated

Chromatography is used to separate the components of a mixture and can be carried out in a range of different ways.

a) A suitable example of a ‘carrier gas’ in gas chromatography is

• Chlorine

• Nitrogen

• Steam

• Not possible to state, as there should be a vacuum

Which gas is the least suitable as a carrier gas in Gas-Liquid Chromatography?

• Argon

• Carbon Dioxide

• Oxygen

• Nitrogen

Separation is achieved in gas chromatography due to the components in the mixture having different

• Interactions with the stationary phase.

• Interactions with the mobile phase.

• Colours

• Solubility in the moving solvent.

What type of detector that our lab use?

• Flame Ionization

• Thermal Conductivity

• Electron Capture

• Nitrogen Phosphorous

Which one factor of these factors that does NOT affect the retention time of a substance?

• column length

• affinity

• volatility

• freezing point