Organic Synthesis and Analytical Techniques

How can haloalkanes be synthesised through nucleophilic substitution?

• Alcohol reacts with chloride compound e.g.(HCl) to produce haloalkane

• halide substitutes OH group to form water

How to purify organic liquids?

Use a separating funnel to remove the organic layer from the aqueous layer

Dry organic layer with anhydrous salt (e.g. MgSO₄ or CaCl₂)

redistil at …

Draw a distillation apparatus

Draw a reflux apparatus

gap

What are fragment ions?

parts of molecular ions that were broken down through fragmentation

What happens when covalent bonds absorb IR radiation?

The bonds vibrate more and absorb energy.

Which atmospheric gases absorb IR radiation and contribute to global warming?

CO₂, H₂O and CH₄.

How can an alcohol be identified from an IR spectrum?

By an O–H absorption peak.

How can an aldehyde or ketone be identified from an IR spectrum?

By a C=O absorption peak.

How can a carboxylic acid be identified from an IR spectrum?

By a C=O peak and a broad O–H peak.

What can IR spectroscopy be used for besides identifying organic compounds?

Monitoring air pollutants (e.g. CO and NO) and measuring ethanol in breathalysers.