Spectroscopy Revision Helpsheet Lesson Objective Task(s) Understand that the fragmentation of a molecular What is a molecular Explain what Explain how ion gives rise to a characteristic relative ion? fragmentation is and fragmentation patterns abundance spectrum that may give information write an equation to can be used to give about the structure of the molecule represent it. information about the structure of a molecule. Know that the more stable X+ species give higher Describe how the Compare the stability Explain why acylium peaks, limited to carbocation and acylium (RCO+) relative abundance of of primary, secondary ions are stable ions a peak is related to the and tertiary fragments. stability of the cation carbocations. Be able to use IR spectra to identify functional State the range of the Explain what the Describe the similarities groups. region. fingerprint region is. and differences ‘fingerprint’ between the IR spectra of alcohols, carbonyls, esters and carboxylic acids. Understand that nuclear magnetic resonance Describe what is meant Describe how shielding influences the chemical gives information about the position of 13C or 1H by shielding. of an atom. atoms in a molecule
Spectroscopy Revision Helpsheet Lesson Objective Task(s) Understand that the fragmentation of a molecular ion gives rise to a characteristic relative abundance spectrum that may give information about the structure of the molecule What is a molecular ion? Explain what fragmentation is and write an equation to represent it. Explain how fragmentation patterns can be used to give information about the structure of a molecule. Know that the more stable X+ species give higher peaks, limited to carbocation and acylium (RCO+) ions Describe how the relative abundance of a peak is related to the stability of the cation Compare the stability of primary, secondary and tertiary carbocations. Explain why acylium ions are stable fragments. Be able to use IR spectra to identify functional groups. State the range of the ‘fingerprint’ region. Explain what the fingerprint region is. Describe the similarities and differences between the IR spectra of alcohols, carbonyls, esters and carboxylic acids. Understand that nuclear magnetic resonance gives information about the position of 13C or 1H atoms in a molecule Describe what is meant by shielding. Describe how shielding influences the chemical of an atom.
spectroscopy_revision_helpsheet.docx