MedVision ad

Identifying cations and anions in mixtures (1 Viewer)

isuperx3

New Member
Joined
Nov 3, 2008
Messages
5
Gender
Female
HSC
2010
Hey can anyone find a flowchart that can identify cations and anions in mixtures without flame tests?
Also How do i distinguish between calcium and barium ions without any fluorides ions added in the solution?
help please :( my prac assessment is this wednesday.
 

ibbi00

Member
Joined
Sep 6, 2009
Messages
771
Gender
Male
HSC
2010
To test for the presence of barium ions you add sulfate ions. (i.e Sulfuirc acid)
To test for the presence of calcium ions you add carbonate ions. (i.e Sodium carbonate)
You observe for a white precipitate in both cases.

Jacaranda textbook has a pretty good flow chart. Try and get your hands on one.
 

fullonoob

fail engrish? unpossible!
Joined
Jul 19, 2008
Messages
465
Gender
Male
HSC
2010
in the exam they will provide a unique flowchart to you
you use that flowchart to record info not the one off your memory.
 

Mature Lamb

wats goin on
Joined
May 14, 2009
Messages
1,117
Gender
Male
HSC
2010
Uni Grad
2015
in the exam they will provide a unique flowchart to you
you use that flowchart to record info not the one off your memory.
I think he's saying he needs to develop a flowchart for a practical assessment task
 

Toranilor

Member
Joined
Mar 7, 2010
Messages
38
Location
Wherever there is pie.
Gender
Male
HSC
2010
Don't know if it'l help, but I wrote a little song to help me remember the tests;

I am the very model of a qualitative ion test(er)

To be sung to "Major General's Song", by Guilbert and Sullivan (Pirates of Penzance)

Cation Verse;
So you want to learn about cations well that's really great.
Lead, P-B 2 plus with chloride forms a white precipitate.
Just know the confirmation test and you'll be ready to a-go.
When combined with iodide it goes a canary yellow.

Iron III goes muddy brown in presence of a hydroxide,
Confirmation; it goes blue with K-4 ferric cyanide.
Iron II hydroxide goes a pretty shade of green I hear,
It changes purple potassium permanganate into a clear.
*Verse again*
Copper with hydroxide will go blue with some definity
A deep blue with ammonia 'cause of it's high alkalinity
Both Barium and Calcium will form a white precipitate
When combined with a free floating ion that is sulfate.

Barium hoever, goes yellow with a flaming test
Calcium goes white with flouride, don't worry about all the rest
*Chorus*
So now you're done with cations, let move sraight on to anions,
'cause they make up just one half of the qualitative ion test.

Anion Verse;

First you take solution and add some of H-N-O-three.
If blubbles form it has some carbonate with a great certainty.
Ensure the effervesence halts, you've got no time to stand and wait.
To your now acidic solution add some barium nitrate.

You'll find that you have sulfate if your test tube turns a pretty white,
Be sure to remove all of it, you don't want to wait out all night.
Then you add ammonia to make your solution alkaline, (8-10 pH)
Add more barium, with phosphate white precipitate you'll find.

Once again nitric acid to solution acidify,
If solute forms with silver then you have an ion of Chloride.

The tests of confirmation are of relative simplicity.
Silver chloride will never dissolve in high acidity.
Sulfate ions and silver, not one precipitate you'll find,
As opposed to carbonate, precipitates out white you mind.

Phosphate tuns yellow with silver, soluble HNO-three
But nitric acid dissolves white barium phosphate as you'll see.
For something really complex try amonium molybnum-oxide
A yellow precipitate forms with an acid of nitride.

So that's all the anions and all the cations as well.
Surely in ionic tests you'll now be doing really well.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top