Organic,inorganic And Halide Tests Flashcards
Whats the result of the test for an alkene
Bromine water go from orange to colourless
Whats the test for an halogenoalkane
- Add NaOH(aq) and warm
2.acidify with HNO3 - Add AgNO3(aq)
Whats the result for the test for haloalkanes
A precipitate of AgX forms (colour depends on the halogen present)
Test for alcohol (primary and secondary
Add acidified K2Cr2O7
Result for test for alcohol
Orange colour of potassium dichromate turns green (only primary and secondary alcohols and with aldehydes)
The 2 tests for aldehydes
Warm with Fehlings solution
Warm with Tollens solution
Results for tests for aldehydes
Fehlings - blue turns to red precipitate
Tollens - silver mirror forms
Test for carboxylic acids
Add NaHCO3 (aq)
Result for test for carboxylic acids
CO2 given off
Simple ways you can guess a compound or substance
Solid,liquid or gaseous
Is it acidic
Simple test for polar groups
Does the compound dissolve in water
Uses for mass spectrometry
Identifying relative atomic mass and relative molecular mass
Identification of organic molecules
What’s a useful tool to identify organic molecules
Fragmentation
Whats the test for an alkene
Bromine water
How are organic molecules tested in mess spectrometry
Electro spray
How is fragmentation useful
It can show us the rough composition of the molecule
What type of mass spectrometry is really useful for identifying organic molecules
High resolution mass spectrometry
Why is high resolution mass spectrometry useful
It uses real values for atoms so you get an exact mass from the molecule
What is the first stage for time of flight mass spectrometry
Vacuum
What is the second stage for time of flight mass spectrometry
Ionisation
What is the third stage for time of flight mass spectrometry
Acceleration
What is the fourth stage of time of flight mass spectrometry
Ion drift
What is the fifth stage of time of flight mass spectrometry
Detection
What is the sixth stage of time of flight mass spectrometry
Data analysis
What is the use of low resolution mass spectrometry
Is is useful as it allows you to see the relative abundance of different isotopes
How to find relative atomic mass from mess spectrum
( %(1) x mass(1) + %(2) x mass(2) )/100
Why is vacuum useful
It prevent particles losing velocity due to resistance
What happens in electro spray ionisation
The molecule is dissolved and then sprayed and the water evaporates leaving a proton
What happens in electron gun ionisation
Electrons are shot at the atom and the electrons are repelled off the atom ionising it
What happens in the acceleration stage
The ionised molecules and atoms will be attracted and repealed by charged plates and acceleration
What happens in the ion drift stage of mass spectrometry
The accelerated ions accelerate down a clear path where the lower mass ions will fly faster than those with larger mass
What happens in the detection stage
The ion collides with a charged plate and accepts an electron producing a current which is detected by the computer
What happens in data analysis
The data from the detection plate if graphed and interpreted
How does infrared spectroscopy work
IR Em waves are emitted towards the molecules and cause them to wiggle as they absorb certain frequencies
How do you read a Ir spectroscopy graph
The peaks downwards are areas where frequencies are absorbed
What value is used to show frequencies absorbed
Wave number Cm^-1
What is the fingerprint region
A region where you can check against known molecules to test which one is which
What is the way you can tell what a molecule is composed of
By comparing known value against dips in the graph
Where is the fingerprint region
Anything below 1500 cm^-1
What is the test for halides
Acidified silver nitrate
Why can’t we use HCl instead of HNO3
HCl contains a chlorine and will give false results
Why does the test have to be acidified
To remove OH^1- and CO3^2-
What is the flour precipitate for flouride ions
No precipitate
What colour is the precipitate for Chloride ions
White ppt
What colour is the precipitate for bromide ions
Cream ppt
What colour is the precipitate for iodide
Pale yellow ppt
What’s the test to make sure the precipitate is silver chloride
Dissolves in dilute ammonia
What test makes sure the precipitate is silver bromide
Dissolves in concentrated ammonia
What test is used to make sure the precipitate is silver iodide
Does not dissolve in concentrated ammonia
What is in the ionisation stage
The particles are ionised either through electro spray or electron impact
