CHEMISTRY PRACTICAL 34 DISCUSSION

[samantha liyanage]

AHLAM U R RIGHT FB7 CONTAINED THESE IONS BUT PLZ ANS MY QUESTION was it written that add ammonia in excess TO FB6??? No ! this means that we had to add only 1cm3 of ammonia not in excess !!
SO IT WAS POSSIBLE TO HAVE ZN IONS IN FB6

didnt it just say to add ammonia ?
it didnt say drops or excess right ?

 

[happyperson]

didnt it just say to add ammonia ?
it didnt say drops or excess right ?

yeah, it didn't mention the amount.

 

[Wamiqktk]

yeah, it didn't mention the amount.

oh I GOT IT WRONG THEN SHITTTT

 

[JutniP]

what were the ions in fb7?
i wrote iodide carbonate and cloride
cloride becasue we added agno3 to the solid and added ammonia so it dissolved.. im not sure if zinc is right though because youve added agno3 already...idk you tell

I dd the same thing and i didnt write sulphate or sulphite anywhere.my praactical sucked bigtimee :'(

 

[Sohail Shaheen]

With the start of the question, it was written that u have to write the observation in excess of reagent added. so we had to add amonia in excess, and write the observation accordingly.

 

[Sohail Shaheen]

Howcome u people r saying dat sulfite was the possibility. the ppt was insoluble while testing FB6. no?

 

[unkidd]

it was zinc,carbonate and iodide :/

i wrote fe carbonate and iodide going to lose the mark

 

[Shaoli Hassan]

Wasn't there ammonium in FB7. I mean I held a damp red litmus paper over it and it turned blue.....

 

[Shaoli Hassan]

Howcome u people r saying dat sulfite was the possibility. the ppt was insoluble while testing FB6. no?

I wrote sulfite as the possibilty too

 

[Wamiqktk]

Wasn't there ammonium in FB7. I mean I held a damp red litmus paper over it and it turned blue.....

No FB7 had CARBONATE, IODIDE AND ZINC!!! CONFIRM...

 

[maestro maisam]

FB 6---> Had these ion's : Mg, Al, Sulphate & Sulphite ---> In confirmatory test it had Mg!
FB 7---> Had these ion's : Zn, I, Carbonate.

 

[Shaoli Hassan]

But th

No FB7 had CARBONATE, IODIDE AND ZINC!!! CONFIRM...

But there must be a fourth ion too...I mean let's say the compounds are ammonium carbonate and zinc iodide......it's a guess.

 

[Shaoli Hassan]

FB 6---> Had these ion's : Mg, Al, Sulphate & Sulphite ---> In confirmatory test it had Mg!
FB 7---> Had these ion's : Zn, I, Carbonate.

If I am not wrong, I think it was mentioned in the question not to write about Aluminium and Calcium. So I think it must be Mg and ammonium...not very sure though.

 

[happyperson]

FB 6---> Had these ion's : Mg, Al, Sulphate & Sulphite ---> In confirmatory test it had Mg!
FB 7---> Had these ion's : Zn, I, Carbonate.

In confirmatory test, it did not have Mg as the precipitate was insoluble in excess NaOH.

 

[maestro maisam]

In confirmatory test, it did not have Mg as the precipitate was insoluble in excess NaOH.

Bro it was Mg.. Im like 200% certain about this!

 

[maestro maisam]

But th

But there must be a fourth ion too...I mean let's say the compounds are ammonium carbonate and zinc iodide......it's a guess.

FB 7 had Zinc Carbonate and Potassium Iodide... Since K is the most reactive element and it cannot be displaced we couldn't detect its presence.. SO , FB7 had Zn, Carbonate , Iodide ion's!!!

 

[happyperson]

Bro it was Mg.. Im like 200% certain about this!

Please clear how, as when i did the confirmatory test, i added NaOH in excess and as per the qualitative analysis notes, Mg is insoluble in excess NaOH and it was when i added so how come it was Mg??

 

[maestro maisam]

Please clear how, as when i did the confirmatory test, i added NaOH in excess and as per the qualitative analysis notes, Mg is insoluble in excess NaOH and it was when i added so how come it was Mg??

Yes! The given solution gave a white ppt with NaOH and was insoluble in excess NaOH ( I exactly don't remember the observations both mine and in qualitative analysis ) As far as i remember "Mg" is insoluble in excess NaOH and "Al" is soluble in excess NaOH .. Which actually confirmed that it had "Mg" .. Besides this according to many sources FB6 was a liquid solution of Magnesium Sulphate...