Exam 11: Theories of Covalent Bonding

One can safely assume that the 3s- and 3p-orbitals will form molecular orbitals similar to those formed when 2s- and 2p-orbitals interact.According to molecular orbital theory,what will be the bond order for the Cl₂⁺ ion?

Overlap of two sp² hybrid orbitals produces a $\pi$ bond.

Which of the following statements relating to molecular orbital (MO)theory is incorrect?

According to molecular orbital theory,what is the bond order in the O₂⁺ ion?

Carbon uses ______ hybrid orbitals in ClCN.

The nitrosonium ion,NO⁺,forms a number of interesting complexes with nickel,cobalt,and iron.According to molecular orbital theory,which of the following statements about NO⁺ is correct?

In molecular orbital theory,combination of two 2p atomic orbitals may give rise to either $\sigma$ or $\pi$ type molecular orbitals.

Explain what is meant by a node (or nodal plane)in a molecular orbital and draw sketches of the following orbitals,indicating at least one nodal plane in each one. a.a $\sigma$ * orbital b.a $\pi$ * orbital

Sketch the shapes of the $\sigma$ _1s and $\sigma$ _1s* molecular orbitals formed by the overlap of two hydrogen 1s atomic orbitals.

According to valence bond theory,the triple bond in ethyne (acetylene,C₂H₂)consists of

Describe the bonding in ethylene (ethene,C₂H₄)according to valence bond theory.Be sure to indicate the orbital hybridization on the carbon atoms.Draw a diagram clearly showing at least one bond of each type which occurs in the molecule.

According to molecular orbital theory,all diatomic molecules with an even number of electrons will be diamagnetic.

Which one of the following statements about orbital hybridization is incorrect?

A molecule with the formula AX₄E uses _________ to form its bonds.

a.What simple experiment could you perform to show that a substance is paramagnetic? b.What microscopic (atomic/molecular)feature must a substance possess in order to be paramagnetic? c.Can it be predicted whether or not all homonuclear diatomic ions,X₂⁺,will be paramagnetic? Explain.

a.In the context of valence bond theory,explain the difference in geometry between a $\sigma$ and a $\pi$ bond.Use a real molecule to illustrate your answer. b.What two important differences are there in the properties of $\sigma$ and $\pi$ bonds,in terms of how they affect the structure and reactivity of molecules?

Determine the shape (geometry)of PCl₃ and then decide on the appropriate hybridization of phosphorus in this molecule.(Phosphorus is the central atom. )

In the valence bond treatment,a $\pi$ bond is formed when two 2p orbitals overlap side to side.

Valence bond theory explains the bonding in diatomic molecules such as HCl without resorting to the use of hybrid orbitals.

Valence bond theory predicts that tin will use _____ hybrid orbitals in SnF₅^-.