S3.2 Functional groups: HL Part 2 Flashcards
Magnetic resonance imaging (MRI)
A medical technique used to produce a detailed view of the internal organs in the human body.
Proton nuclear magnetic resonance (1H NMR)
An analytical technique that is used to determine the number of different chemical environments that contain protons in an organic compound.
Spin states
A spinning atomic nucleus creates a magnetic field. The different spin states (parallel and antiparallel) are created by the direction of the spin.
Radio frequency signal
An oscillation in the frequency range of 3 kHz to 300 GHz, which corresponds to the frequency of radio waves.
Resonance frequency
The frequency of radiation that causes a proton to undergo spin-flip.
Chemical environment
A group of equivalent protons that all have the same resonance frequency. Also known as the hydrogen environment.
Equivalent protons
Protons that are in the same chemical environment.
Non-equivalent protons
Protons that are in different chemical environments.
Deshielding
The process by which an electronegative atom such as oxygen causes a group of equivalent protons to absorb downfield on a 1H NMR spectrum.
Splitting patterns
The splitting of a peak on an 1H NMR spectrum into clusters of peaks.
Spin–spin coupling
The interaction between the magnetic fields of adjacent protons.
n+1 rule
Used to determine the splitting pattern produced by a group of equivalent protons.
Relative intensities
The relative intensity of each proton in a splitting pattern.
What analytical techniques are used to determine the structure of a molecule with an empirical formula of C3H6O2?
Mass spectrometry, IR spectroscopy, and ¹H NMR spectroscopy.
How is the molecular mass of a molecule determined in the context of C3H6O2 analysis?
Using mass spectrometry, the molecule’s molecular mass was found to be 74.
(C3H6O2)=(3 × 12.01 g/mol) + (6 × 1.01 g/mol) + (2 × 16.00 g/mol) =74.08
Which functional group is identified in C3H6O2 through IR spectroscopy?
A carboxyl group (COOH).
What does ¹H NMR spectroscopy reveal about the molecule C3H6O2?
It exhibits three different chemical environments for protons.
What is the structure of the molecule with an empirical formula of C3H6O2 based on analytical data?
Propanoic acid
