← Spectroscopic data
• Achieved, identifying discrete aspects of the structure of organic molecules using teacher-provided spectroscopic data.
• Merit, determining the structure of organic molecules using spectroscopic data.
• Excellence, justifying the structure of organic molecules by integrating spectroscopic data.
Spectroscopic data is limited to mass, infrared (IR) and ¹³C nuclear magnetic resonance. Aspects of structure are limited to molar mass and molecular formulae, functional groups, and the carbon framework including structural isomers. ✓
• state what you understand about the techniques and their applications
• interpret IR spectra to identify the presence or absence of carbonyl groups and/or hydrogen bonding (N–H, O–H), and use IR to judge possible structures
• identify carbon environments for a given molecular structure
• use ¹³C data to judge possible structures from the number of environments, from the magnitude of the shifts, and from both together
• interpret the molecular ion and isotopic variations, molecular mass, number of nitrogens (odd or even), number of carbons (from the ¹³C isotope ratio), and the presence of Cl, Br and I
• make basic interpretations of primary fragmentations (single bond breakages)
• integrate knowledge from all three techniques to evaluate the identity of unknowns ✕
2 How this connects to your other standards
This standard is pure detective work, and it borrows its evidence from elsewhere.How this connects
Where the content on this page comes from and where it goes:
Organic compounds (91391): the molecules you are identifying Explanatory note 4 limits this standard to alkanes, alkenes, alcohols, haloalkanes, amines, aldehydes, ketones, carboxylic acids, amides, acid chlorides and esters: exactly the families taught in 91391. You cannot deduce a structure you cannot draw. The workbook says as much: students should be fluent in drawing structures, identifying functional groups and evaluating structural isomers before starting here. ℹWhat this standard is, in one box
AS91388 · Chemistry 3.2 · Internal · 3 credits.• Achieved, identifying discrete aspects of the structure of organic molecules using teacher-provided spectroscopic data.
• Merit, determining the structure of organic molecules using spectroscopic data.
• Excellence, justifying the structure of organic molecules by integrating spectroscopic data.
Spectroscopic data is limited to mass, infrared (IR) and ¹³C nuclear magnetic resonance. Aspects of structure are limited to molar mass and molecular formulae, functional groups, and the carbon framework including structural isomers. ✓
What you are expected to be able to do
The workbook’s specific learning outcomes for this standard:• state what you understand about the techniques and their applications
• interpret IR spectra to identify the presence or absence of carbonyl groups and/or hydrogen bonding (N–H, O–H), and use IR to judge possible structures
• identify carbon environments for a given molecular structure
• use ¹³C data to judge possible structures from the number of environments, from the magnitude of the shifts, and from both together
• interpret the molecular ion and isotopic variations, molecular mass, number of nitrogens (odd or even), number of carbons (from the ¹³C isotope ratio), and the presence of Cl, Br and I
• make basic interpretations of primary fragmentations (single bond breakages)
• integrate knowledge from all three techniques to evaluate the identity of unknowns ✕
There is no ¹H NMR in this standard
Explanatory note 3 limits the data to mass, IR and ¹³C NMR. If you have met the n+1 splitting rule, integration, ¹H chemical shift tables or the δ 9.7 aldehyde proton, those all belong to ¹H NMR and cannot be assessed here. Spending revision time on them is time you are not spending on carbon environments, which is where the marks actually are.Practice for this standard covers the whole topic — flashcards and quiz.