CBSE Questions for Class 11 Medical Chemistry Chemical Bonding And Molecular Structure Quiz 10 - MCQExams.com

The relatively high boiling point of $$HF$$ is due to 
  • Hydrogen bonding
  • Covalent bonding
  • Unshared electron pair on F
  • Being a halogen acid
The enolic form of acetone contains:
  • 9 sigma bonds, 1 pi bond and 2 lone pairs
  • 8 sigma bonds, 2 pi bond and 2 lone pairs
  • 10 sigma bonds, 1 pi bond and 1 lone pair
  • 9 sigma bonds, 2 pi bond and 1 lone pair
Which of the following option is correctly matched
  • $$ S_{3}O_{9} $$ : contains no S-S linkage
  • $$ S_{2}O^{2}_{6 } $$ ; contains -O-O-linkage
  • $$ (HPO_{3})_{3} $$; contains P-P linkage
  • $$ S_{2}O^{2-}_{8} $$ ; contains S-S linkage
Water has high heat of vaporisation due to:
  • Covalent bonding
  • H-bonding
  • Ionic bonding
  • None of the above
Which contains strongest H-bond?
  • $$O-H...S$$
  • $$S-H...O$$
  • $$F-H...F$$
  • $$F-H...O$$
On the following hydrides which has the lowest boiling point?
  • $$NH_3$$
  • $$PH_3$$
  • $$SbH_3$$
  • $$AsH_3$$
In which of the following compounds does hydrogen bonding occur?
  • $$SiH_4$$
  • $$LiH$$
  • $$HI$$
  • $$NH_3$$
which of the following statements is false
  • $$ H_{2}PO_{2} $$, $$ H_{3}PO_{3} $$,$$ H_{3}PO_{4} $$ all are tribasic and reducing in nature
  • Among anions, $$ NO_{3}^{-} $$, $$ SO^{2-}_{3} $$,$$ SO^{2-}_{4} $$,$$ S_{2}O_{4}^{2-} $$,$$ H_{2}SO_{4} $$ , $$ SO^{2-}_{3} $$ is basic reducing nature
  • Number of anions $$ SO^{2-}_{3} $$,$$ SO^{2-}_{4} $$, $$ SO^{2-}_{4} $$, and $$ H_{2}SO_{4} $$,$$ SO^{2-}_{3} $$
  • Number of lone pair(s) electrons on Xe atoms in $$ XeF_{2} $$,$$ XeF_{4} $$,$$ XeF_{6} $$ are 3,2,and 1 respectively.
An electrically charged atom or a group of atoms is known as:
  • A meson
  • A proton
  • An ion
  • A cyclotron
Which of the following is not correct
  • A sigma bond is weaker than $$\pi$$ bond
  • A sigma bond is stronger than $$\pi$$ bond
  • A double bond is stronger than a single bond
  • A double bond is shorter than a single bond
The bond angle of water is $$104.5^{\circ}$$ due to 
  • Repulsion between lone pair and bond pair
  • $$sp^3$$ hybridization of O
  • Bonding of $$H_2O$$
  • Higher electronegativity of O
In the sigma bond
  • Sidewise as well as end to end overlap of orbitals take place
  • Sidewise overlap of orbitals take place
  • End to end overlap of orbitals takes place
  • None of the above
In $$N_2$$ molecule, the atoms are bonded by:
  • One $$\sigma$$ and Two $$\pi$$
  • One $$\sigma$$ and one $$\pi$$
  • Two$$\sigma$$ and one$$\pi$$
  • Three $$\sigma$$ bonds.
The number and type of bonds between two carbon atoms in calcium carbide are:
  • One sigma, one pi
  • One sigma, two pi
  • Two sigma, one pi
  • Two sigma, Two pi
The covalency of nitrogen in $$HNO_3$$ is:
  • 0
  • 3
  • 4
  • 5
Which can be described as a molecule with residual bonding capacity
  • $$BeCl_2$$
  • $$NaCl$$
  • $$CH_4$$
  • $$N_2$$
The double bond between the two carbon atoms in ethylene consists of
  • Two sigma bonds at right angles to each other
  • One sigma bond and one pi bond
  • Two pi bonds at right angles to each other
  • Two pi bonds at an angle of $$60^{\circ}$$ to each other
Toluene has 
  • $$6\sigma$$ and $$3\pi$$ bond
  • $$9\sigma$$ and $$3\pi$$ bond
  • $$9\sigma$$ and $$6\pi$$ bond
  • $$15\sigma$$ and $$3\pi$$ bond
Which compound has zero dipole moment?
The number of $$\sigma$$ bonds in o-xylene is 
  • $$6$$
  • $$9$$
  • $$12$$
  • $$18$$
In which one of the following changes there are transfer of five electrons
  • $$Mn{O}_{4}^{-}\rightarrow {Mn}^{2+}$$
  • $$Cr{O}_{4}^{2-}{Cr}^{3+}$$
  • $$Mn{O}_{4}^{2-}Mn{O}_{2}$$
  • $${Cr}_{2}{O}_{7}^{2-} 2{Cr}^{3+}$$
The type of bonding in $$HCl$$ molecule is 
  • pure covalent
  • polar covalent
  • highly covalent
  • $$H-$$ bonding
Peroxide bond is present in
  • $$MgO$$
  • $$CaO$$
  • $$Li_2O$$
  • $$BaO_2$$
The number of $$\pi$$ bonds in 3-hexyne-1-ene is 
  • $$1$$
  • $$2$$
  • $$3$$
  • $$4$$
Acetylene molecules contain 
  • $$5\sigma$$ bond
  • $$4\sigma $$ bond and $$1\pi$$ bond
  • $$3\sigma$$ and $$2\pi$$
  • $$3\sigma$$ and $$3\pi$$
In $$PO_{4}^{3-}$$ ion the formal charge on the oxygen atom of $$PO$$ bond is
  • $$+1$$
  • $$-1$$
  • $$-0.75$$
  • $$+0.75$$
The enolic form of acetone contains 
  • $$8\sigma$$ bonds, $$2\pi-$$ bonds and $$1$$ lone pairs
  • $$9\sigma$$ bonds, $$1\pi-$$ bonds and $$2$$ lone pairs
  • $$9\sigma$$ bonds, $$2\pi-$$ bonds and $$1$$ lone pairs
  • $$10\sigma$$ bonds, $$1\pi-$$ bonds and $$1$$ lone pairs
In which of the following combination hybridisation of central atom (*) does not change ?
  • $$H_{2}O + CO_{2}$$
  • $$H_{3}BO_{3} + OH^{-}$$
  • $$BF_{3} + NH_{3}$$
  • None of these
Number of S - S bond is $$H_{2}S_{n}O_{6}$$ :
  • n
  • (n - 1)
  • (n - 2)
  • (n + 1)
A : tetracyanomethane
B : carbondioxide
C : benzene
D : 1, 3-butadiene
Ratio of $$\sigma$$ and $$\pi$$ bonds is in order : 
  • A = B < C < D
  • A = B < D < C
  • A = B = C= D
  • C < D < A < B
In which of the following cases C-C bond length will be highest?
  • $$CH_3-CF_3$$
  • $$FCH_2-CH_2F$$
  • $$F_2CH-CHF_2$$
  • $$CF_3-CF_3$$
A diatomic molecule has a dipole moment of 1.2 D. If the bond length is $$1.0 \times 10^{-8} \ cm$$, what fraction of charge does exist each atom?
  • 0.1
  • 0.2
  • 0.25
  • 0.3
Correct statement(s) about dipole moment of $$R_3NO$$ and $$R_3PO$$ is/are :
  • dipole moment of $$R_3NO$$ > dipole moment of $$R_3PO$$
  • dipole moment of $$R_3NO$$ < dipole moment of $$R_3PO$$
  • Experimental dipole moment of $$R_3PO$$ > theoretical dipole moment of $$R_3PO$$
  • Experimental dipole moment of $$R_3PO$$ < theoretical dipole moment of $$R_3PO$$
Which of the following statements is incorrect for sigma and $$\pi$$ - bonds formed between two carbon atoms?
  • Sigma - bond is stronger than a $$\pi$$- bond
  • Bond energies of sigma and $$\pi$$- bonds are of the order of 264 kJ/mol and 347 kJ/mol
  • Free rotation of surrounding atoms about a sigma-bond is allowed but not in case of a $$\pi$$- bond
  • Sigma- bond determines the direction between carbon atoms but a $$\pi$$- bond has no primary effect in this regard
How many lone pairs of electrons are in resonance of the given compound?
73017.PNG
  • $$4$$
  • $$2$$
  • $$3$$
  • $$6$$
Which of the following compounds has zero dipole moment?
The total number of lone pairs in chlorate ion is:
  • $$8$$
  • $$4$$
  • $$6$$
  • $$2$$
Give the correct order of initials T or F for following statements. Use T if statement is true and F if it is false :
(i) The order of the repulsion between different pair of electrons is $$l_{p} - l_{p} > l_{p}- b_{p} > b_{p}- b_{p}$$
(ii) In general, as the number of lone pair of electrons on central atom increases, value of bond angle from normal bond angle also increases
(iii) The number of lone pair on O in $$H_{2}O$$ is 2 while on N in $$NH_{3}$$ is 1 
(iv) The structures of xenon fluorides and xenon oxyfluorides could not be explained on the basis of VSEPR theory 
  • TTTF
  • TFTF
  • TFTT
  • TFFF
Which of the following molecular species is/are having $$\pi_{2p}$$ as H.O.M.O. (highest occupied molecular orbital):
  • $$N_2^-$$
  • $$O_2^{2+}$$
  • $$NO^+$$
  • $$B^+_2$$
Select correct statements regarding $$\sigma$$ and $$\pi$$-bonds :
  • $$\sigma$$-bond lies on the line joining the nuclei of bonded atoms
  • $$\pi$$-electron cloud lies on either side to the line joining the nuclei of bonded atoms
  • $$(2p\pi 3d\pi)$$ Pi-bond is stronger than $$(2p\pi - 3p\pi)$$ Pi-bond
  • $$\sigma$$-bond has primary effect to decide direction of covalent bond, which $$\pi$$-bond has no primary effect in direction of bond.
How many sigma bonds are present in a molecule of diethyl either $$C_{2}H_{5}OC_{2}H_{5}$$ ?
  • 14
  • 12
  • 8
  • 16
Which of the following molecules has as $$O-O$$ bond?
  • $$H_2S_2O_8$$
  • $$H_2S_2O_7$$
  • $$H_2SO_5$$
  • $$H_2S_2O_6$$
Which of the following has no lone pair of electrons?
  • $$NO$$
  • $$CO$$
  • $$NH_3$$
  • $$O_2$$
How many sigma and pi bonds are present in toluene ?
  • $$10\sigma$$ and $$3\pi$$ bonds
  • $$12\sigma$$ and $$3\pi$$ bonds
  • $$15\sigma$$ and $$3\pi$$ bonds
  • $$6\sigma$$ and $$3\pi$$ bonds
State true or false:
The term chemical bond does not express the existence of strong forces of attraction between the atoms.
  • True
  • False
In $${NO_{3}}^{-}$$ ion, number of bond pair and lone pair of electrons on nitrogen atom are :
  • $$2,2$$
  • $$3,2$$
  • $$1,3$$
  • $$4,0$$
The number of $$sp^{2}-sp^{2} \sigma$$ bond in given compound is:
73030.PNG
  • $$4$$
  • $$5$$
  • $$3$$
  • $$6$$
The molecule in which an atom is associated with more than $$8e^{-}s$$ is known as hypervalent molecule. All hypervalent molecules must have $$d\pi - p\pi $$  bonding but the molecule having back bonding need not have always $$d\pi - p\pi $$ bonding.

Which of the following molecule is not having $$d\pi - p\pi $$ bonding?
  • $$SO_{2}$$
  • $$P_{4}O_{10}$$
  • $$H_2O$$
  • $$B_{3}N_{3}H_{6}$$
The ratio of number of lone pairs in the central atoms of $$NH_3$$, $$H_2O$$ and $$XeF_{2}$$ is:
  • $$3:2:1$$
  • $$2:1:3$$
  • $$1:2:3$$
  • $$2:3:1$$
In the analysis of an organic compound, it was found that it contains 7 carbon atoms, there are two C = C bonds and one $$C\equiv C$$ bond. This compound is a hydrocarbon. Hydrocarbons have only carbon and hydrogen elements. On structural analysis it was found that it is covalent in nature and expected structure is given above. The ratio between the pure and hybrid orbitals is?

25634_710955a49cc441a68370bc918dcbf84c.png
  • $$7:10$$
  • $$8:7$$
  • $$5:9$$
  • $$1:2$$
0:0:1


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