cations and anions (1 Viewer)

[xeriphic]

i'm getting abit confused, i kept thinking cations are distinquished with the flame test while anions are through precipatation

though in some question i realise the fact that we use solubility rules to tell which cations are present, so can anyone tell me when to actually use flame tests and why thanks

 

[kalinda]

the flame test is only good for Ca and Ba - can also be used for Cu
thats the main reason that both Ca and Ba are included in the syllabus cause its mostly the flame test that can distingush the two

 

[kalinda]

btw they are cations

 

[cko]

both calcium and barium will form a ppt with sulfate ions (i thinkit was) to form a wht ppt. to distinguish btwn the two ions u use the flame tesat: calcium burns to produce an 'apple' green flame while barium burns to produce a 'brick' red flame.

 

[xiao1985]

errr, cko, i think you got it the other way around ^^b

 

[cko]

haha oh yeh oopsie thx xiao umm.. calcium burns to produce a red flame and barium burns to produce a grenn flame. To make it easier to remember i usually think calcium=bones and red=blood: put those two together and u got blood n bones!! bit gory but yeah... it works!