Topic 9 Seperate Chemistry 2 Flashcards
What colour do these ions turn when under a blue flame
Lithium ions-
Sodium ions-
Potassium ions-
Calcium ions-
Copper ions-
Li+ red flame
Na+ yellow flame
K+ lilac flame
Ca+ orange-red flame
Cu+ blue-green flame
What colour precipitate is formed when you add sodium hydroxide(NaOH) to these metal compounds
Aluminium-
Calcium-
Copper-
Iron(II)-
Iron(III)-
Al3+ white at first but goes colourless in excess of NaOH
Ca2+ white
Cu2+ blue
Fe2+ green
Fe3+ brown
What is the test for ammonia
Add sodium hydroxide to it and heat it and should give off ammonia gas which can be detected by holding damp red litmus palate over it and will turn blue
Also has distinctive smell
Why must a test for every ion be unique
To be able to differentiate between them
How do you test for carbonate ions
Add a dilute acid and then that should cause a fizz which is the carbon dioxide made then use limewater test to test for the carbon dioxide
How do you test for sulfate
Add dilute hydrochloric acid
Then add barium chloride solution and a white precipitate should be formed
How do you test for chloride, bromide, and iodide ions
Add some dilute nitric acid with few drops of silver nitrate solution
What colour do precipitates of chloride, bromide, and iodide produce
Chloride - white precipitate
Bromide - cream precipitate
Iodide -yellow precipitate
Why are instrumental methods of ions used
Very sensitive detect very small amounts of substance
Very fast
Very accurate and don’t involve human error
How does flame photometry work
Use intensity of a wavelength to indicate the concentration of an ion in a solution
How are alkanes and alkenes different
Alkenes contain double bonds and alkanes don’t
What is the general formula for an alkane
C n H 2n+2
What is the general formula for an alkene
C n H 2n
How are alkanes saturated
They have formed as many bonds as they can and have no double bonds
Megan (meth)
Eats (eth)
Peanut (prop)
Butter (but)