Chapter 4

The order of relative strengths of bonds formed by sp, ${\mathrm{sp}}^2$ and ${\mathrm{sp}}^3$ hybrid orbitals is (1) $\mathrm{sp}>{\mathrm{sp}}^2>{\mathrm{sp}}^3$ (2) $\mathrm{sp}<{\mathrm{sp}}^2<{\mathrm{sp}}^3$ (3) $\mathrm{sp}={\mathrm{sp}}^2={\mathrm{sp}}^3$ (4) $\mathrm{sp}<{\mathrm{sp}}^2>{\mathrm{sp}}^3$

The F-F bond in ${\mathrm{F}}_2$ is weak because of (1) the high electronegativity of fluorine (2) the small size of fluorine and the repulsion between the lone pairs of electrons in adjacent atoms (3) fluorine being the first member of the halogen family (4) the reactivity of fluorine

The average bond energy of C-C bond is $342\mathrm{KJ}$ mol ${}^1$. The bond energy of Si-Si bond is $(1)=342\mathrm{KJ}$ mol ${}^{\prime }$ (2) $<342\mathrm{KJ}$ mol 1 (3) $>342\mathrm{KJ}$ mol (4) cannot be predicted

Bond length decreases with (1) increase in size of the atom (2) increase in the number of bonds between atoms (3) decrease in the number of bonds between atoms (4) decrease in bond angle

The correct order of the arrangement of bond length is (1) ${\mathrm{F}}_2>{\mathrm{N}}_2>{\mathrm{Cl}}_2>{\mathrm{O}}_2$ (2) ${\mathrm{Cl}}_2>{\mathrm{F}}_2>{\mathrm{O}}_2>{\mathrm{N}}_2$ (3) ${\mathrm{O}}_2>{\mathrm{Cl}}_2>{\mathrm{N}}_2>{\mathrm{F}}_2$ (3) ${\mathrm{F}}_2>{\mathrm{Cl}}_2>{\mathrm{N}}_2>{\mathrm{O}}_2$

The correct order of the O-O bond length in ${\mathrm{O}}_2,{\mathrm{H}}_2{\mathrm{O}}_2$ and ${\mathrm{O}}_3$ is (1) ${\mathrm{O}}_2>{\mathrm{O}}_3>{\mathrm{II}}_2{\mathrm{O}}_2$ (2) ${\mathrm{O}}_3>{\mathrm{II}}_2{\mathrm{O}}_2>{\mathrm{O}}_2$ (3) ${\mathrm{II}}_2{\mathrm{O}}_2>{\mathrm{O}}_3>{\mathrm{O}}_2$ (4) ${\mathrm{O}}_2>{\mathrm{II}}_2{\mathrm{O}}_2>{\mathrm{O}}_3$

${\mathrm{NH}}_3$ has a net dipole moment but boron trifluoride has zero dipole moment because (1) $\mathrm{B}$ is less electronegative than $\mathrm{N}$ (2) $\mathrm{F}$ is more electronegative than $\mathrm{H}$ (3) ${\mathrm{BF}}_3$ is pyramidal while ${\mathrm{NH}}_3$ is planar (4) ${\mathrm{BF}}_3$ is trigonal planar while ${\mathrm{NII}}_3$ is pyramidal

Which of the following statements is wrong? (1) HCl molecule in the vapour state is an example of polar covalent bond. (2) Among ${\mathrm{CH}}_2{\mathrm{Cl}}_2,{\mathrm{BF}}_3,{\mathrm{NF}}_3$ and ${\mathrm{ClO}}_2$, only ${\mathrm{BF}}_3$ has zero dipole moment. (3) The dipole moment of ${\mathrm{NH}}_3$ is less than ${\mathrm{NCl}}_3$. (4) Anhydrous IICl is a bad conductor of clectricity but aqueous IIC1 is a good conductor.

The electronegativity values of $\mathrm{C},\mathrm{H},\mathrm{O},\mathrm{N}$ and $\mathrm{S}$ are $2.5,2.1,3.5,3.0$ and $2.5$, respectively. Which of the following bonds is most polar? (1) $\mathbf{C}-\mathrm{H}$ (2) $\mathrm{N}-\mathrm{H}$ (3) $\mathrm{S}-\mathrm{H}$ (4) O-H

The bonds between $\mathrm{P}$ atoms and $\mathrm{Cl}$ atoms in $\mathrm{P}{\mathrm{Cl}}_5$ are likely to be (1) ionic with no covalent character (2) covalent with some ionic character (3) covalent with no ionic character (4) ionic with some metallic character