Covalent Bond

Q. Which of the following will contain the highest number of oxygen atoms?

1. All
2. 1g of O atom
3. 1 g of molecule
4. 1 g of molecule

Q. While filling up of electrons in the atomic orbitals, the 4s orbital is filled before the 3d orbital but reverse happens during the ionization of the atom. Explain why?

Q. In hydrogen atom, energy of first excited state is $–3.4\text{eV}$. Then find out K.E. of same orbit of hydrogen atom.

1. $+3.4\text{eV}$
2. $+6.8\text{eV}$
3. $-13.6\text{eV}$
4. $+13.6\text{eV}$

Q. The species, having bond angle of ${180}^o$ is:

1. $P{H}_3$
2. $BeC{l}_2$
3. $H_{2}O$
4. $S{O}_2$

Q.

What is the difference between covalent bond and hydrogen bond?

Q.

(i)

Elements X, Y and Z have 4, 5 and 7 valence electrons respectively.

Write the molecular formula of the compounds formed by the elements individually with hydrogen.

(ii) Which of these compounds will have highest dipole moment?

Q. Choose the correct stability order of group $13$ elements in their +1 oxidation state.

Q. The values of electronegativity of atoms A and B are 1.20 and 4.0 respectively. The percentage of ionic character of A - B bond is

1. 50 %

2. 43 %

3. 72.24%

4. 55.3 %

Q.

What is lowest energy structure, in terms of formal charge?

Q. Homolytic fission of a covalent bond leads to the formation of

1. Free radicals
2. Carbocation
3. Carbanion
4. Both A & B

Q. Peroxide linkage is present in:

1. $H_2{O}_2$
2. $Ba{O}_2$
3. $O{F}_2$
4. $H_2{S}_2{O}_8$

Q.

Which of the following solid is isotropic?

1. Molecular

2. Metallic

3. Amorphous

4. Ionic

Q. Assertion (A): Silicones are water repelling in nature.

Reason (R): Silicon are organosilicon polymers, which have $(-R_{2}SiO-)$ as repeating unit.

1. Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$.
2. Both $A$ and $R$ are correct and $R$ is not the correct explanation of $A$.
3. $A$ is not correct but $R$ is correct.
4. Both $A$ and $R$ are not correct
   

Q. Explain the following:

A Gallium has higher ionization enthalpy than Aluminium.

B Boron does not exist as \(B^{3+}\) ion

C Aluminium forms \([AlF_6]^{3-}\)- ion but Boron does not form \([BF_6]^{3-}\)- ion.

D \(PbX_2\) is more stable than \(PbX_4\).

E \(Pb^{4+}\) acts as an oxidizing agent but \(Sn^{2+}\) acts as a reducing agent.

F Electron gain enthalpy of chlorine is more negative as compared to fluorine.

G \(Tl (NO_3)_3\) acts as an oxidizing agent.

H Carbon shows catenation property but lead does not.

I \(BF_3\) does not hydrolyze.

J Why does the element silicon not form a graphite-like structure whereas carbon does.

Q. Arrange the following compounds in increasing order of their boiling points.
$C{H}_{3}CHO,C{H}_{3}C{H}_{2}OH,C{H}_{3}OC{H}_3,C{H}_{3}C{H}_{2}C{H}_3$

Q. The polymer containing strong intermolecular forces like hydrogen bonding is:

1. Natural rubber
2. Polystyrene
3. Teflon
4. Nylon-6, 6

Q. Which of the following molecule has highest bond energy? 1) F- F 2) N-N 3) C-C 4) O-O

Q. When $Zn$ converts from melted state to its solid state, it has hcp structure, then find the number of nearest atoms.

1. $6$
2. $8$
3. $12$
4. $4$

Q. State the type of bonding in the following molecule:

(b) calcium oxide.

Q. i f the 1st ionization energy of H atom is 13.6 eV, then the 2nd ionization energy of He atom is 27.2 eV 40.8 eV 54.4 eV 108.8 eV

Q. In $P_4{O}_6$ how many O atoms are bonded to one P atom

Q.

What are triple covalent bonds ?

Q. According to the valence bond theory the hybridization of central metal atom is $ds{p}^2$ for which one of the following compounds ?

1. $N{a}_2\left[NiC{l}_4\right]$
2. $K_2\left[Ni\right(CN{)}_4]$
3. $NiC{l}_2.6H_{2}O$
4. $\left[Ni\right(CO{)}_4]$

Q. Which of the following statements about hydrogen are correct?

1. Hydrogen ion, $H^{+}$, exists freely in solution.
2. Hydrogen has three isotopes of which protium is the most common.
3. Hydrogen never acts as cation in ionic salts.
4. Dihydrogen does not act as a reducing agent.

Q.

Which of the following elements can show covalencey greater than 4?
(a) Be (b) P (c) S (d) B

Q.

Question 17

The electronic configurations of the elements A, B and C are given below. Answer the question on the basis of these configurations.

A $1s^2$ $2s^2$ $2p^6$

B $1s^2$ $2s^2$ $2p^6$ $3s^2$ $3p^3$

C $1s^2$ $2p^6$ $2p^6$ $3s^2$ $3p^5$

The bond between B and C will be

(a) ionic

(b) covalent

(c) hydrogen

(d) coordinate

Q.

Aspartame is a non-nutritive sweetner . Assuming that both amide and ester bonds are hydrolyzed in the stomach, the amino acid obtained is

1. 
2. 
3. BOTH (A) AND (c)
4. none of these

Q. If HCl molecule is completely polarized, so expected value of dipole moment is 6.12D (debye), but experimental value of dipole moment is 1.03D. Calculate the percentage ionic character

1. 83
2. 50
3. zero
4. 17

Q.

Draw the electron dot structure for ${\mathrm{F}}_2$.

Q. Assertion: $S{F}_6$ cannot be hydrolysed but $S{F}_4$ can be.
Reason: Six F atoms in $S{F}_6$ prevent the attack of $H_{2}O$ on sulphur atom of $S{F}_6$.

1. Both assertion and reason are correct statements, and reason is the correct explanation of the assertion
2. Both assertion and reason are wrong statements.
3. Assertion is wrong but reason is correct statement
4. Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion.
5. Assertion is correct but reason is wrong statement.