<p>yeah you won't be able to smell either long enough to be able to differentiate between the two without choking
NO3 is easier to identify because you can see the fumes, Cl is extremely unreliable even with MnO2 and sulphuric acid</p>
<p>I once did the confirmatory tests for CL-they were successful..However it turned out I was dealing with nitrate</p>
<p>OK one more thing,what all precautions do we have to write for salt analysis?</p>
<p>weird. either you had a contaminated sample or you neutralized the sodium carbonate extract with HCL</p>
<p>add copper turnings after you add H2SO4 to distinguish between nitrate and cl, NO3 will give you dark brown fumes</p>
<p>wow your CBSE pracs are tough!</p>
<p>I've never written a single precaution for any chem prac in my life!</p>
<p>the best way to see if u have a NO3- in ur salt is to add a small amt of copper turnings to the sample followed by a few drops of conc H2SO4. The sides of the test tubes turn brownish</p>
<p>they never asked us to write precautions for salt analysis- itz reqd only for the core expt</p>
<p>thanks u guyz</p>
<p>Ok,question for chromatography,we measure the distance travelled by ink from the baseline right?Do we also measure the distnce travelled by solvent form baseline or from the edge of the paper?</p>
<p>and you could try adding manganese dioxide and conc sulphurid acid to your sample and heating in the hope of seeing greenish yellow fumes but this has worked for me only twice in my life :(</p>
<p>measure everything from the reference line.</p>
<p>this thread has become an instant messanger :D</p>
<p>thats what its meant to be</p>
<p>ok,so finally,we ttake all distances from same refernce line,right?
and the rf valus are around 8 and 9,correct?</p>
<p>also,what knind of viv-questions were u asked regarding core experiments?</p>
<p>oh, and heres a toast to my 800th post</p>
<p>i got SOL- so a lot of my viva stuff were based on surface chem. Also, be sure to learn the tonz of Qs related to permanganometry- like why H2SO4 is added for FAS while makin the soln, why its added in the conical flask, etc... these were some of the ext examiner's fave questions</p>
<p>wow your syllabus seems HUGE!</p>
<p>yah... its huge n boring.. i really hate chem n I know its gonna kill my aggregate in the boards</p>
<p>what exactly is FAS?</p>
<p>also,what questions were u asked regarding sols?ZShud I now learn surface chemistry from the textbook,or are the questions in the lab manual enuf?</p>
<p>Man am I glad I'm in an ISC school...</p>
<p>FAS == Mohrs Salt == (NH4)2SO4.FeSO4.6H20</p>
<p>i guess the lab manual covers most of it... for sols- well stuff based on Hardy Schulz rule, lyophobic, lyophillic and examples.. and also stuff on coagulation, coagulation factor, etc</p>