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Chemical Bonding and Molecular Structure

Long Answer Type

171.

On the basis of VSEPR theory, predict the shapes of given molecules: PCl₅ and SF_6.

450 Views

172.

Discuss the shape of the following molecules using VSEPR model:
BeCl₂, BCl₃, SiCl₄, AsF₅, H₂S, PH₃

1233 Views

173.

State and explain hybridisation.

139 Views

Short Answer Type

174.

What are the necessary conditions for hybridisation?

327 Views

175.

What are the different types of hybridisation in s and p atomic orbitals?

108 Views

Long Answer Type

176.

Discuss in brief sp³ hybridisation. Explain the formation of methane and ethane.

1378 Views

177.

Discuss in brief sp² hybridization (hybridization in C = C bond). Discuss the molecular orbital structure of ethylene (first member of alkene).

Or

Draw diagrams showing the formation of a double bond between carbon atoms in C₂H₄.

441 Views

Short Answer Type

178.

Apart from tetrahedral geometry, another possible geometry for CH₄ is square planar with four H atoms at the corners of the square and the C atom at its centre. Explain why CH₄ is not square planar?

345 Views

Long Answer Type

179.
On the basis of hybridisation, discuss the orbital structure of: (i) BeF₂ (ii) BH3.

(i) Orbital structure of BeF₂ :

To form BeF₂ molecule, an electron gets promoted from filled 2s orbital to vacant 2p orbital. Therefore, the excited configuration of Be atom is

In BeF₂, Be atom is sp hybridised i.e. two hybrid orbitals are directed along a straight line with a bond angle equal to 180°. Each sp hybrid orbital overlaps axially with 2p half-filled orbital of F atom to form sigma Be – F bonds.

(ii) Orbital structure of BH₃:
The electronic configuration of B (Z = 5) is 1s² 2s²2P^1.

In BH₃, B atom is sp² hybridised and the three hybrid orbitals overlap axially with the orbital of the hydrogen atom to from three sigma B–H bonds.

The shape is trigonal planar.

212 Views

Short Answer Type

180.

The central atoms in CH₄, NH3 and H₂O are all said to have similar hybridisation but the bond angle H – A – H (where A is C, N or O) is different in each case. Explain stating in which case it is maximum and in which case it is minimum.

171 Views