8 Analysis Separate Flashcards
What is a flame test?
A test to identify metal ions (cations)
What is the colour of the flame produced from a lithium containing compound?
Crimson
What is the colour of the flame produced from a copper containing compound?
Green
What is the colour of the flame produced from a sodium containing compound?
Yellow
What is the colour of the flame produced from a potassium containing compound?
lilac
What is the colour of the flame produced from a calcium containing compound?
Orange-red
Other than flame tests, how can metal ions be identified?
Use of sodium hydroxide
Which solutions produce white precipitates on addition of sodium hydroxide?
Solutions containing aluminium, magnesium, calcium ions
How can a solution of aluminium ions be distinguished from calcium and magnesium ones?
Its precipitate will dissolve in excess sodium hydroxide
What is the colour of the precipitate formed from the addition of sodium hydroxide to a solution containing copper (II) ions?
Blue
What is the colour of the precipitate formed from the addition of sodium hydroxide to a solution containing iron(II) ions?
Green
What is the colour of the precipitate formed from the addition of sodium hydroxide to a solution containing iron(III) ions?
Brown
What is the test for carbonates?
Add an acid to generate carbon dioxide gas
What is the test for halides?
Add silver nitrate and nitric acid to generate a solid silver halide precipitate
What are the colours of the silver halides?
Silver chloride white, silver bromide cream, silver iodide yellow
What is the test for sulfate ions?
Add barium chloride and hydrochloric acid, forms white precipitate
What is an instrumental method?
Use of scientific technology to perform chemical analysis
What are the three advantages of instrumental methods?
They are accurate (gives correct results), sensitive (only needs a small sample to work), rapid (a lot faster than other tests)
What is flame emission spectroscopy?
An instrumental analysis tool for identifying metal ions
How is flame emissions spectroscopy carried out?
Sample placed in a flame, light emitted is passed through a spectroscope to give a spectrum which can be compared to a reference
