Molecular Orbital Theory

To determine the correct statement, let's examine each option:

1. Dipole moment of ammonia is due to orbital dipole and resultant dipole in same direction.

   Ammonia (NH₃) has a trigonal pyramidal molecular geometry, which leads to a net dipole moment. In this molecule, the lone pair of electrons on nitrogen creates an orbital dipole, and the bond dipoles from the N-H bonds point towards the nitrogen, aligning with the orbital dipole. Hence, the resultant dipole is significant and points in the same general direction as the orbital dipole.

2. O₂, H₂ show bond dipole due to polarisation.

   Both O₂ and H₂ are homonuclear diatomic molecules with nonpolar covalent bonds. Since atoms of the same element share electrons equally, no bond dipole or polarization exists.

3. Dipole moment is scalar quantity.

   Dipole moment is a vector quantity, not scalar. It has both magnitude and direction.

4. In BF₃, bond dipoles are zero but dipole moment is higher.

   Boron trifluoride (BF₃) has a trigonal planar structure. Although each B-F bond has a polarity, the symmetrical arrangement causes the bond dipoles to cancel out, resulting in a net dipole moment of zero.

Thus, the correct statement is: Dipole moment of ammonia is due to orbital dipole and resultant dipole in same direction.

The problem requires identifying the total number of and bonds in an ethene ( ) molecule.

Structure of Ethene ( ): The ethene molecule consists of two carbon atoms ( ) and four hydrogen atoms ( ).

Bonding Details:

• Carbon-Carbon Double Bond: The double bond between the two carbon atoms consists of one bond and one bond.
• Carbon-Hydrogen Bonds: Each of the two carbon atoms forms a single bond with each of two hydrogen atoms, totaling four bonds from carbon to hydrogen.

Total Bonds:

• Total bonds:
• Total bonds:

Therefore, ethene has 5 and 1 bonds.