SUB:CHEMISTRY
TOPICS:CHEMICAL BONDING & MOLECULAR STRUCTURE
TIME ALLOWED : 60 MIN.
MAX MARKS: 70
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TEST DATE:
Important directions
All questions are compulsory
Marks will be deducted for every incorrect response ( Only for objective questions )
Q .Nos 1 to 10 carry 3 marks each and 1/3 marks will be deducted for every incorrect response
Q. Nos 11 to 25 carry 1 mark each .
Q Nos 25 to 30 carry 2 marks each.
1.The fluoride, whose value of dipole moment is not equal to zero
(a) XeF4
(b) CF4
2.If N2 is converted into
N2+ ,,its
(a) decreases
(c) SF4
(d) PF5
bond length
(b) increases
(c) remains unchanged (d) none
1.XeF4
2.PCl5
3.BF3
4.CCl4
(a) only 1
(b) 1 and 3
(c) 1,2 and 3
(d) 1,2 and 4
(c) H2S
(d) Trans 2 –butene
3.Octet rule is violated by
4.Which of the following has dipole moment
(b) [Ni( CN)4]2-
(a) 1,4 dichlorobenzene
5.Which molecule /ion out of the
(a)
N2+
6 .In
PO43-,the
following does not contain unpaired electrons
(b) O2
(c) O22-
(d) B2
formal charge on the oxygen atom of P-O bond is
(a)+1
7.The bond order of
(a)1.75
ClO4-
(b) -1
is equal to
(b) 1.5
8.No of lone pairs in XeOF4
is
(a) 2
(b) 1
9.Which among the following will have triple bond order?
(b)CN-
(a)CO
(c)-0.75
(d) +0.75
(c) 1.66
(d) 1
(c)3
(d)
4
(c) NO+
(d) all of these
10.Among the following LiCl ,BeCl2, BCl3, CCl4 which will have the lowest melting point and the highest solubility
(a) CCl4 ,LiCl
(b) LiCl ,CCl4
(c) BeCl3, BCl3
11.What is the geometry and type of hybrid orbital present about the central atom in BF 3
(d) BCl3 ,BeCl2
?
12.Calculate the number of bond pairs and lone pairs in XeF4
13.He2 does not exist .Explain why ?
14.How many sigma bonds are present in Benzene ?
15.Name the d-orbital involved in sp3 d hybridization in PCl5?
16.Draw the shape of XeOF4.
17.Calculate the number of π bonds in Tetracyanomethane [ C (CN)4]
18.Arrange the following compound according to covalent character AlCl3. NaCl , MgCl2, SiCl4
19.Which one has higher polarizing power& explain why ; Cu+ and Na+
20.Which one has higher dipole moment NH3 and BF3 ?
21.Calculate the number of antibonding electrons in O2.
22.What is the hybridization of ICl4- ?
23.What is the bond angles in XeO3F2 ?
24.Calculate change in hybridization when AlCl3 is changed into AlCl4-
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25.What is % p character in P4 molecule ?
26.Write down the difference between sigma and pi bond ?
27.Draw the resonating structures of CO32-. Also calculate the bond order of carbonate ion
28.Although C-O bond in CO2 is polar but CO2 is non polar molecule .Explain why?
29.Write down the rule of drawing resonating structure ?
30.O2 is paramagnetic in nature .Explain with the help of MO diagram ?
This section contains two questions. This question contains statements given in
2 columns which
have to be matched statement in column-I are labeled as A ,B ,C,D while the statement in column
are labeled as p, q ,r ,s
Any given statement in column-I can have correct matching with one or
more statement(s) in column –II [4M x2]
31.
(A)
SiF4
(p) Pyramidal molecule
(B)
NH3
(q) Tetrahedral molecule
(C)
BeF2
(r)
Zero dipole moment
(D)
BF3
(s)
Linear molecule
32.
(A)
C2
(B)
O2
(C)
NO
(D)
N2
+
(p)
< (
(q)
Paramagnetic
(r)
Triple bond
(s)
Diamagnetic
=
)
PASSAGE BASED QUESTIONS(Q.N0 33 to 35) ( 2M x 3 +1 = 7M )
Dipole moment is a vector quantity and is depicted by a small arrow with tail on the positive centre and head
pointing towards the negative centre. The shift in electron density is symbolized by crossed arrow ( ) above the
Lewis structure to indicate the direction of the shift. In case of polyatomic molecules the dipole moments not
only depend upon the individual dipole moments of bonds known as bond dipoles but also on the spatial
arrangement of various bonds in the molecule.
33. If the dipole moment in C-Cl
bond in
is 1.5 D .What is the dipole moment of
34. If the bond angle of Y- X-Y(
with increase in the value of
) is
α?Explain.
α Then how does the value of bond dipole changes
35.Which of the following molecule can have zero dipole moment
(a)1,3,5 –Trichlorobenzene (b) 1,3 –Dichlorobenzene (c) 1,2,6 –Trichlorobenzene (d) 1,2,4 –Trichlorobenzene
36.In which of the pairs, the dipole moment of the
(a)NH3
,
NF3
(c)Trans -2- butane and Cis- 2-butene
first species is greater than
the second?
(b) BF3 ,BCl3
(d)1,4 -Dichlorobenzene ,Benzene -1,4 -diol
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