organic analysis Flashcards
What is the result of adding bromine water to an alkene?
Orange → colourless
This indicates the presence of a double bond in the alkene.
What are the precipitate colors formed when haloalkanes react with NaOH, warm HNO3, and AgNO3?
- AgCl - white
- AgBr - cream
- AgI - yellow
These colors help identify different haloalkanes.
What happens to primary and secondary alcohols when reacted with K2Cr2O7 (VI) and H2SO4?
Orange → green
This indicates the oxidation of alcohols to ketones or aldehydes.
What is the result of warming an aldehyde with Fehling’s reagent?
Blue → red precipitate
This indicates the presence of an aldehyde.
What happens when a carboxylic acid reacts with NaHCO3?
Fizzes and produces CO2
This reaction helps identify carboxylic acids.
What is mass spectrometry primarily used for?
Finding the relative molecular mass of organic compounds
It involves ionizing compounds and measuring their mass to charge ratios.
What does the molecular peak in a mass spectrum represent?
The highest peak furthest right (the molecular mass)
This peak indicates the molecular weight of the compound.
What is fragmentation in mass spectrometry?
When ions break up as they are ionized, producing smaller molecular mass ions
Fragment ions can provide structural information about the compound.
What is the purpose of high-resolution mass spectrometry?
To measure masses to three or four decimal places
This allows for precise determination of molecular formulas.
What is the effect of stronger bonds on bond vibrations?
Stronger bonds vibrate faster (at higher frequency)
This affects the interpretation of infrared spectra.
How does infrared spectrometry work?
IR radiation is absorbed by covalent bonds, increasing their vibrational energy
Bonds can only absorb radiation at their natural frequency.
What is the fingerprint region in infrared spectroscopy?
Below 1500 cm-1
It contains unique peaks for specific substances.
What do extra peaks in an infrared spectrum indicate?
The presence of impurities
Comparing spectra can help determine the purity of a compound.
What is the wavenumber range for N-H bonds in amines?
3300-3500 cm-1
This range is crucial for identifying amines in infrared spectra.
What is the wavenumber range for C=O bonds in carbonyl compounds?
1680-1750 cm-1
This range includes aldehydes, ketones, and carboxylic acids.
What is the impact of greenhouse gases on infrared absorption?
They absorb IR radiation, contributing to the greenhouse effect
Human activities have increased this effect, leading to global warming.
Fill in the blank: The natural frequency of a bond is in the ______ region of the electromagnetic spectrum.
[infrared]
This frequency is unique to each bond type.
