24thx aieeee and everyone...but here are correct answers
Ans6=6M NH3
Ans8=a,d
Ans9=b,c
single choice correct
Q1 WHich pair can form alloy ?
a)Zn,Pb
b)Fe,Hg
c)Fe,C
d)C,Pt
Q2 consider [Ag(NH3)2]+,[Ag(CN)2]-,[Ag(S2O3)2]3-
Which of the following are true abt these ??
a)Ag+ acts as lewis base
b)hybd of Ag+ is sp2
c)the all are gud reducing agent
d)all are linear
QHardness of transiiton metals is due to ?
a)large atomic size
b)metallic bonding
c)covalent bond
d)high ionization energy
Q4The oxidn state in metal carbonuyl is generally _____
Q5 the no. of ions formed on dissolving FeSO4(NH4)2SO4.6H2O is ??
Q6 te only cations present in slightly acidic soln are Fe3+,Zn2+,Cu2+.Find reagent which when added to soln will separate them Fe3+ in one step
Q7 which of the following are paramagnetic and colored
a)K2Cr2O7
b)(NH4)2[TiCl]6
c)VOSO4
d)K3[Cu(CN)4]
more than one correct
Q8which of folowing are ionic
a)ZnCl2
b)LiCl
c)HgCl2
d)AgCl
Q9 K4[Fe(CN)6] is used in identification of
a)Fe2+
b)Fe3+
c)Cu2+
d)Cd2+
-
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43 Answers
2424refer wiki for Q8...it clearly shows LiCl and HgCl2 as ionic compounds
11As per J.D LEE
Zn Cl2 and Cd Cl2 are ionic, but Hg Cl 2 is covalent (Pg no. 842)
The halides and alkyls of lithium are far more covalent than the corresponding sodium compounds, and bcoz of this covalency, they r soluble in organic solvents. (Pg no. 310)
1q2) b
Ag+ has completely filled d so cannot reduce and the d orbital cannot be used for hybridisation hence sp2
q5) 5 ions this is a double salt
q6) Zn(ll) is in group 6
Fe (lll) is in group 3 n Cu(ll) in group 2
by adding the group reagent of group 3 i.e. NH4OH in NH4Cl we will get reddish brown ppt. of Fe(OH)3 which is filtered off to separate Fe(lll) from the solution.
q7. C Vanadium(V) 1 electron in d and blue coloured as given in NCERT
q8) A, D by fajans rules
24@tush....i am getting confused becoz JD lee says something else and wiki something else
@rick
ans2,6,8 is wrong
ans5,7 are rite....
can u explain ans 5 a bit ??
1Q.1) c. fr sure.
Q.2) It should be d).
Ag - 4d10 5s1 , Ag+ - 4d10
and in [Ag(NH3)2]+ , [Ag(CN)2]- , [Ag(S2O3)2]3- , its sp hybridised.
and it acts as a lewis acid.
so, the only statement right is d) all are linear.
Q.3) Actually , all the carbides, borides , arsenides etc. of transition metals are strong and hard compounds. so, i think with reference to that it might be due to covalent bonding.
i also remember sea borg's model of atomwhich said metallic bonding to be weak.
Q.6) put some sodium acetate in the mixture.
CH3COONa + Fe3+ → [ Fe3(OH)2 (CH3COO)6]+ (a blood red colour solution)
thus , the other two ions remain undissolved.
Also , ammonium sulphide can be used as it gives black precipitate with Fe3+.
Q.7 ) Certainly V4+ is coloured , with one unpaired electron left.
Q.8) I feel it should be a) , b) , d).
as ionisation of HgCl2 is not so high. this is the reason for which it can't give the chromyl chloride test , while others can.
Q.9) It should be a) , b) , c) , d).
as b) , c) , d) give direct precipitate with the reagent while , a) Fe2+ gives precipitate using this reagent as an intermediate.
Fe2+ + K3[Fe(CN)6] → Fe3+ + K4[Fe(CN)6]
then these products form Fe4 [ Fe(CN)6]3 ( turnbull's blue )
so, practically, it should be all , but depends a) has been considered or not.
1ans. 6 is also right.
ans.8 is still doubtful.
ans.9 is surely wrong. as Cd2+ gives bluish white precipitate with the reagent.
1q)9-yup and fe2+ is also detected by it....so surely ans is wrong....
1well... I gave ans of q8) as a,d n u told it's wrong....[2]
for 6) we can use many reagents... the one i told is the one which
we have used in our school practicals (see qualitative analysis)
in q 9) Fe+3 gives prussian blue
Cu+2 gives reddish brown ppt
@arshad n aieee..
Fe+2 gives turnbull's blue with [Fe(CN)6]+3 not +4
for the Cd+2 test CH3COOH must be added
1in Q5)
we see that it is not a complex as no"box" is there
it is just a double salt
so when we add water all ions are dissociated and show their independent tests
19i doubt the ionic character of lithium chloride !
......mr.mentor,,,can you please remove this circumspect nature of this answer ![4]
1in q8)
the anion is same in all i.e. Cl
by fajans rule smaller the cation, more polarising power hence more covalent
now Li+ and Hg+2 are pretty small
so ans a,d
1The question asks whether LiCl is ionic or not which it surely is.
This can be gauged from the fact that LiCl is used for electrolysis
in extraction of Lithium metal.
NO doubts about its covalent character as well.
Hope this clarifies the doubts. :)
19QUOTING j.d.lee :" the halides and alkyls of lithium are far more covalent than the corresponding sodium compounds and because of this covalency they are soluble in organic solvents"
also, the first element in each of the main groups (Li, Be, B ,C ,N,O,F) differs from the rest of the group,this is partly because the first element is much smaller than the subsequent elements and consequently it is more likely to form covalent compounds (fajan's rule) and complexes !
1Q)4-0
generally metal carbonyls have oxidation states of <+2
and most general is 0
