chem pp33 discussion!!!

[hassam]

24 hours are almost ova........so lets start discussing......we discussed titre.........wat about heating that white powder fa5........by the way i know that ........it was sodium bicarbonate......
The reaction sodium hydrogen carbonate has when heated is that carbon dioxide gas is released, as well as water vapour. When the compound is under heat, the crystaline powder 'bubbles,' and stirs around as the carbon dioxide gas is released. Over time the powder is heated, the entire compound gradually decreases noticably in size and weight as the water vapour escapes as well. The crystaline powder (solid) never changes state, and after 15-20 minutes of heating, the compound will appear similar, for the exception of decreased weight and amount.
this above explanation is from wiki ansers......so sure u people detcted CO2 And not ammoniaaa..........can anybody tell me when we had to use that heated powder again in the question.....was there any such part....??

 

[aquariangurl]

Observation on heating of FA5 was so weird, like it didn't make sense for a long time, so I just wrote spitting & formation of bubbles & yes white fumes released..then after cooling we had to add FA7 to the powder, which showed release of CO2, & then when you test this solution with NaOH & NH3, the most appropriate answer was Ba2+, Is this correct by any chance

 

[mrpaudel]

the FA7 was...Ammonium and bromide ion!! but i didnot write anything in FA5....jus made a table..state the anhydrous value..and thats it!!

 

[hassam]

didnt we had to add to FA6.....the soln to wich sulfuric acid was added......i added fa7 to resulting fa6 soln....nd i belive if m nt wrong it was written over there this thing onlyy

 

[hassam]

fa6 was ammonium and bromide paudel!!!!

 

[hassam]

fa5...that white powder contained sodium bicarbonate..co2 detected on heating....fa6 contained ammonium bromide...wrote redox on adding h2so4 not sure...obs were steamy white fume..red-brown gas evolved near base of test-tube...on adding water to this it dissolved to give colorless soln....on adding fa7 nothing happened...adding lead nitrate resulted in cloudy white ppt and ag no3 resulted in cream ppt.......last part....dont know messed it up wrote Ba and Nitrate ...percentage purity ...was 86.7 percent....and titre got 29.45 as mean value

 

[hassam]

jxt tell me on fa6....there were 3 tests performed...one confirmed ammonium....adding lead nitrate did gave white ppt bt adding silver nitrate also gave cream ppt.......did u ppl got the same

 

[msk]

jxt tell me on fa6....there were 3 tests performed...one confirmed ammonium....adding lead nitrate did gave white ppt bt adding silver nitrate also gave cream ppt.......did u ppl got the same

yeah same result!

 

[hassam]

wat abt heating white powder fa5 msk

 

[hassam]

wat was percent purity

 

[ahsan99]

@ hassam , i dont think it was redox..when Bromide ions react with Sulfuric acid
Hydrogen isnt produced..Hbr + S0 2 + Br2 are produced
khair ..can you please repeat that percentage purity qtn?
one was percentage of iron, then uncertainity..and the other..?

and if that FA7 was sulfuric acid then u get white ppt with both Ag and Pb
due to sulfate ions ( in case of Br- ions u get white and cream ppt ---FA6)

 

[msk]

wat abt heating white powder fa5 msk

CO2 was released that turned lime water milky...on further heating NaHCO3 decomposed!

 

[boy2011]

in FA5 i wrote just gas is evolved.nd FA6 WERE ammonium nd bromide ions while FA7 has sulfate ion nd barium i wrote barium cuz it was gvng no ppt wd naoh as wel nh3 so i just wrote dat

 

[ahsan99]

wat abt heating white powder fa5 msk

CO2 was released that turned lime water milky...on further heating NaHCO3 decomposed!

On heating sodium hydrogen carbonate..it was dehydrated (hence it settled at the bottom of the test tube..film) and secondly carbon dioxide was released turning limewater chalky ..rite!

what was that percentage purity qtn..?

 

[hassam]

and also solid moved around and fizzed in the tube....this observation which ll lead u to testing for a gas

 

[intel1993]

jxt tell me on fa6....there were 3 tests performed...one confirmed ammonium....adding lead nitrate did gave white ppt bt adding silver nitrate also gave cream ppt.......did u ppl got the same

yeah same result!

yeah same results........>>>>