testing for ions (1 Viewer)

abbadell

New Member
Joined
Mar 7, 2006
Messages
11
Gender
Female
HSC
2006
Can someone please help me with these questions.
If you are testing for cations. Suppose you perform the test for copper before that for lead. Would you be able to successfully identify whether copper was present. If testing for anions and added the barium chloride to test for sulfate ions before you had tested for chloride ions, would you be able to identify successfully whether sulfate was present.
 

Nakashima

We GLAMOROUS
Joined
Jun 14, 2006
Messages
491
Gender
Female
HSC
2005
Copper forms a blue precipitate with hydroxide. Lead also forms a precipitate with hydroxide. If you had a solution that contained either lead or copper, you'll be able to tell which it is by the colour of the precipitate. If there's a possibility that both were present, then test for lead first using chloride.

Why would you want to test for chloride if you know you've just added barium chloride?

Learn your solubility rules and it's all pure logic.
 

Forbidden.

Banned
Joined
Feb 28, 2006
Messages
4,436
Location
Deep trenches of burning HELL
Gender
Male
HSC
2007
abbadell said:
Can someone please help me with these questions.
If you are testing for cations. Suppose you perform the test for copper before that for lead. Would you be able to successfully identify whether copper was present. If testing for anions and added the barium chloride to test for sulfate ions before you had tested for chloride ions, would you be able to identify successfully whether sulfate was present.
You are such an awesome person like me who doesnt completely know their solubility rules by heart .. Im just gonna copy it from a sheet


Soluble Ionic Compunds


Group 1 and ammonium

nitrates

acetates (ethanoates)

chlorides, bromides and idodides (except silver and lead ions)

sulfates (except silver, lead, barium, strontium, and calcium ions)

Insoluble Ionic Compunds


carbonates, sulfites and phosphates (except group 1 and ammonium compunds)

hydroxides and oxides(except Group 1, ammonium, barium, strontium and calcium ions)

sulfides (except Groups 1, 2 and ammonium ions)



NOTE: I cant write down the ion configuration, because I cant input exponentials ...

C'mon, you know hydroxides are OH- with a valency of 1 right ? And an Aluminium ion is Al2+ with two extra electrons right ?
 

Riviet

.
Joined
Oct 11, 2005
Messages
5,593
Gender
Undisclosed
HSC
N/A
f3nr15 said:
NOTE: I cant write down the ion configuration, because I cant input exponentials ...
Type (sup)1+(/sup) but using [ ] brackets around each sup, this will produce a superscript, ie an exponential. You may also like to know that to produce a subscript ie the small numbers in chemical formulae like CH4, type (sub)1+(/sup) but using [ ] brackets just like for the superscript.
f3nr15 said:
And an Aluminium ion is Al2+ with two extra electrons right ?
I believe it's Al3+, as it appears in group 3 of the periodic table.
 
Last edited:

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

Top