Which type of bond is formed by the head-on overlap of atomic orbitals?

A. Pi bond

B. Sigma bond

C. Delta bond

D. Phi bond

Which molecule contains resonance structures?

A. CH4

B. H2O

C. O3

D. N2

In a pi bond, the overlapping of orbitals occurs:

A. Head-on

B. Sideways

C. Diagonally

D. Perpendicular

Which of the following is NOT a property of sigma bonds?

A. Formed by head-on overlap

B. Stronger than pi bonds

C. Contains two regions of electron density

D. Allows free rotation of bonded atoms

The concept of formal charge is used to:

A. Determine the charge on an ion

B. Predict the magnetic properties of a molecule

C. Assess the distribution of electrons in a molecule

D. Measure the bond strength

a) Explain the difference between sigma (σ) and pi (π) bonds in terms of their formation and spatial orientation. [3]

b) Given a molecule with a double bond, how many sigma and pi bonds would it contain? Justify your answer. [2]

a) What is the significance of formal charge in determining the most plausible Lewis structure for a molecule? [3]

b) For the molecule CO3^2-, calculate the formal charge on the central carbon atom. [2]

a) Define resonance structures and explain their importance in understanding the structure of molecules. [3]

b) For the molecule SO3, draw two possible resonance structures. [2]

a) Describe the role of d-orbitals in the formation of pi (π) bonds. [2]

b) In a molecule with a triple bond, how many sigma (σ) and pi (π) bonds are present? [2]

c) Why are molecules with resonance structures generally more stable than those that can be represented by a single Lewis structure? [3]

a) Explain the concept of formal charge and its significance in drawing Lewis structures. [3]

b) For the molecule NO3^-, determine the formal charge on the nitrogen atom. [2]

c) How does the concept of resonance contribute to the stability of the NO3^- ion? [3]

Which molecule does NOT exhibit resonance?

A. CO3^2-

B. SO4^2-

C. BF3

D. CH4

How many pi bonds are present in ethene (C2H4)?

A. 1

B. 2

C. 3

D. 4

What is the significance of resonance structures in a molecule?

A. They indicate isomers of the molecule

B. They represent the molecule oscillating between structures

C. They show the actual structure of the molecule

D. They depict the delocalisation of electrons in the molecule

In which of the following molecules is the central atom's formal charge zero?

A. CO3^2-

B. NO3^-

C. SO4^2-

D. BF3

Which type of bond is formed by the overlap of two p orbitals perpendicular to the axis connecting the two nuclei?

A. Sigma bond

B. Pi bond

C. Delta bond

D. Phi bond

a) What is the difference between a molecule that has a formal charge and one that has a net charge? [3]

b) Given a molecule with two double bonds, how many sigma (σ) and pi (π) bonds would it contain? [2]

c) Explain the significance of resonance structures in the context of benzene. [3]

a) What is the significance of sigma (σ) bonds in determining the shape of a molecule? [3]

b) For a molecule with sp2 hybridisation, describe the geometry and bond angles you would expect. [2]

c) How does the concept of hybridisation help in explaining the structure and bonding in ethene (C2H4)? [3]

a) Describe the difference between sigma (σ) and pi (π) bonds in terms of their formation. [3]

b) In a molecule of ethyne (C2H2), how many sigma (σ) and pi (π) bonds are present? [2]

c) Explain the concept of resonance using carbonate ion (CO3^2-) as an example. [3]

d) Why is the concept of formal charge important when drawing resonance structures? [2]

a) What is the significance of hybridisation in explaining the bond angles in molecules? [3]

b) Describe the geometry and bond angles in a molecule with sp3 hybridisation. [2]

c) How does the concept of formal charge help in determining the most stable Lewis structure for a molecule or ion? [3]

d) Given a molecule with two single bonds and one double bond to a central atom, determine its hybridisation. [2]

a) Why are molecules with multiple resonance structures generally considered to be more stable than those with a single structure? [3]

b) Describe the electron configuration that leads to the formation of pi (π) bonds. [2]

c) Explain the relationship between the number of sigma (σ) bonds formed by an atom and its hybridisation. [3]

d) Given the molecule SO3, determine the formal charge on the sulfur atom. [2]