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which solution has highest boiling point.
1.1 percent solution of C6H12O6
2.1percent solution of NaCl
3.1 percent solution of ZnSO4
4.1 percent solution of (NH2)2CO

plz post substantial reason also with your answer.

12 Answers

11
Mani Pal Singh ·

consider the vant of factor
u will get ur answer
take the fact of dissociation

1
JOHNCENA IS BACK ·

post a clear reply with whole explanation and solution.

1
Aditya ·

ΔTb=ikbM...i is Vant Hoff factor

i=maximum for both NaCl n ZnSO4 i.e. 2

So ΔTb is maximum....n so boiling pt. is max.

Cheers!

1
JOHNCENA IS BACK ·

ya,thanx..aditya.i also get same ans.but in book ans. is given only NaCl and not ZnSO4.WHY,i do not know.that is why i have posted it.

1
JOHNCENA IS BACK ·

aditya,can you work out why just NaCl and not ZnSO4 too.

1
Aditya ·

No, it should be both as far as i think! The book might have assumed dat there is no dissociation for ZnSO4, which is not correct.

1357
Manish Shankar ·

taking percent solution to be mass/mass

ΔTb=ikbm

ΔTb=ikb(nsolute/Wsolvent)=ikb(Wsolute/Wsolvent)/Msolute

ΔTb=iKb(percentage composition)/M this is not true
as percentage composition=weight of solute/weight of solution
edited
ΔTb=[iKb/M]*K'
ΔTb=Ki/M

so which has i/M greater will have greater boiling point

1
JOHNCENA IS BACK ·

manish sir's reply is helpfu but only a small change would make it perfect.

in third step,

instead of this-

ΔTb=iKb(percentage composition)/M

this should be there-

ΔTb=iKb(constant)/M

as Wsolute/Wsolvent ≠percentage composition
but is constant=1/99.
now i hope it is completely clear.

1
JOHNCENA IS BACK ·

thank you manish sir.

BTW what was your rank in JEE when u gave it?

1357
Manish Shankar ·

hmm

I edited my post

my rank was 747

1
Aditya ·

Thanks bhaiyya :)

1
JOHNCENA IS BACK ·

wow!!!!!!!!!i asked u becoz i never had a chance to talk to any iitian and get guidance by him(except once but i did not dare to ask his rank.but i asked u becoz it makes me feel like i am in a world of top class iitians.)

thank you!

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