Solubility Tests (1 Viewer)

[imprsiv]

Hey, im having trouble with that whole Chemical analysis section in topic 3. WTF is with those tests? like carbonate n sulfate ones n getting precipates. can someone explain them to me, what i need to memorise n noe. exam is 2moro so any replies today will be apprecciated. thankyou gl all

 

[Forbidden.]

In the HSC you are likely be given sample(s) formed from different ions.
It is up to you to deduce the ions present in the sample(s) from the results of the test(s).

Remember them if you want.

EDIT:

You might as well learn them if you want to be safe as this thread says (http://community.boredofstudies.org/17/chemistry/8022/do-i-need-know.html)
I personally can't remember them all either.

 

[mzduxx2006]

Hey, im having trouble with that whole Chemical analysis section in topic 3. WTF is with those tests? like carbonate n sulfate ones n getting precipates. can someone explain them to me, what i need to memorise n noe. exam is 2moro so any replies today will be apprecciated. thankyou gl all

test for cations

add chloride if a white precipitate occurs then Pb is present. if no reaction than SO4 is added and if a white precipitate occurs then this indicates that Ba + Ca are present(which will further be determined by flame tests) if no results are identified then OH is added and a blue precipitate identifies copper, brown precipitate indicates iron 3+ with green precipitate turning brown identifying iron 2+.

Test for anions.

An acid is added, if bubbles appear then carbonate (CO3) is present. If no reaction is seen then barium is added, a white precipitate will indicate SO4, if no result is identified then Ag is added, a white precipitate which darkens in sunlight will identify chloride. If no reaction is seen then iron is added, a green precipitate will identify PO3.