Covalent Bond

Q.

When a chemical bond between two atoms is formed, the potential energy of the system

1. decreases

2. increases

3. remains the same

4. cannot be predicted

Q.

The strength of a bond depends upon

1. free rotation about σ bond

2. resonance in the molecule

3. extent of overlap between the orbitals

4. whether the overlap is axial or sidewise

Q. Among $B_2{H}_6,B_3{N}_3{H}_6,N_{2}O,N_2{O}_4,H_2{S}_2{O}_3$ and $H_2{S}_2{O}_8,$ the total number of molecules containing a covalent bond between two atoms of the same kind is

Q. Multiple covalent bonds exists in :

1. $N_2$
2. $F_2$
3. $C{H}_4$
4. $H_2$

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. Among $B_2{H}_6,B_3{N}_3{H}_6,N_{2}O,N_2{O}_4,H_2{S}_2{O}_{3}and{H}_2{S}_2{O}_8,$ the total number of molecules containing covalent bond between two atoms of the same kind is:

Q. Among the following, van der Waals forces are maximum in:

1. $HBr$
2. $AgBr$
3. $LiBr$
4. $LiCl$

Q.

Question 16

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 molecular formula of the compound formed from B and C will be

(a) BC

(b) $B_{2}C$

(c) $B{C}_2$

(d) $B{C}_3$

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.

(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?