TopHat Chem Ch7 Ex

Using your energy diagram as a guide, which of the following statements are true about the valence atomic orbitals of the carbon atom using the valence bond model (i.e., hybridization) in the fluoroformaldehyde molecule? Select all that apply.

-The hybrid valence orbitals in the valence bond model are all equal in energy. -The hybrid valence orbitals in the valence bond model are higher in energy than the s orbital in the carbon atom without hybridization -To represent the bonding of the carbon atom in the valence bond model the valence electrons of carbon are all unpaired.

What is the bond order of a C-H as predicted by Lewis theory?

1

What is the bond order of the C-H bond in fluoroformaldehyde as predicted by Lewis theory?

1

Which of the following best represents the H-C-H bond angle in methane?

109.5°

Which of the following diagrams correctly represents the hybridization of the oxygen atom in the acylium ion?

3

What is the number of the orbital that holds the lone pair of electrons on the nitrogen atom of the NH2 group of L-histidine?

37

What sort of bond is represented by orbital number 10 of the natural bond orbitals for L-histidine?

A C-C pi bond

What sort of bond is represented by orbital number 2 of the natural bond orbitals for L-histidine?

A C-N sigma bond

What orbitals are involved in the formation of a C-O bond in fluoroformaldehyde? Select all that apply.

A p orbital An sp2 hybrid orbital

What two orbitals are involved in the formation of a C-H bond in fluoroformaldehyde? Select two answers.

An s orbital An sp2 hybrid orbital

What two orbitals are involved in the formation of a C-F bond in fluoroformaldehyde? Select two answers

An sp2 hybrid orbital An sp3 hybrid orbital

Based on the shape of the orbital in the above question and your knowledge of valence bond theory, what type of orbital holds the lone pair on the nitrogen of the NH2 group of L-histidine?

An sp3 orbital

Which of the following best represents the F-C-H bond angle in fluoroformaldehyde?

Around 120°

The molecule above, mandelonitrile, is found in small amounts in some fruit pits. In the body, this compound can release cyanide, making consuming large amount of these fruit pits dangerous. Determine the number of atoms in mandelonitrile that have the following hybridization in valence bond theory:

How many sigma bonds are present in mandelonitrile? 17 How many pi bonds are present in mandelonitrile? 5 sp hybridization? 2 sp2 hybridization? 6 sp3 hybridization? 2

The lowest energy molecule orbital of methane has an energy of around -10 au. Look at the orbital in WebMO. Which of the following best describes this orbital?

It is a non-bonding orbital on the carbon atom because it is a core atomic orbital of carbon and does not match with the energy of any of the hydrogen atom orbitals.

Using the structure for L-histidine above, determine the number of sigma and pi bonds in this molecule based on valence bond theory.

Sigma bonds: 20 Pi Bonds: 3

Using your Lewis structure for fluoroformaldehyde, determine the number of sigma and pi bonds based on valence bond theory.

Sigma bonds: 3 Pi bonds: 1

What is the electron domain geometry of the carbon atom in methane?

Tetrahedral

What is the molecular geometry of the carbon atom in methane?

Tetrahedral

Based on the shape of calculated orbitals and the energy of the molecular orbitals, which of the following best describes the bonding in methane using molecular orbital theory?

The electrons pairs involved in the bonding are each shared between the carbon and all four of the hydrogen atoms. The bond order of a single C-H bond is not able to be determined but the overall bond order of the molecule is 4.

Based on your picture of the orbital overlap for a C-H bond and the energy of the hybridized C atom orbitals, which of the following best describes the bonding in methane using valence bond theory?

The electrons pairs involved in the bonding are each shared between the carbon atom and a single hydrogen atom. Each C-H bond can be described as having a bond order of 1.

What two orbitals are involved in the formation of a C-H bond in methane? Select two answers.

The hydrogen s orbital The carbon sp3 hybrid orbital

What is the electron domain geometry of the carbon atom in fluoroformaldehyde?

Trigonal Planar

What is the molecular geometry of the carbon atom in fluoroformaldehyde?

Trigonal Planar

Using valence bond theory, what is the hybridization of the central atom in a molecule with square planar molecular geometry?

d2sp3

What is the hybridization about the antimony atom in the drawing below?

d2sp3

What is the hybridization about the arsenic atom in the drawing below?

dsp3

What type of orbital overlap is responsible for either of the π-bonds between the carbon and nitrogen atom in the molecule below?

p/p

What type of orbital overlap is responsible for the σ−bond between carbon and nitrogen in the molecule below?

sp/sp

What type of orbital overlap is responsible for the sigma bond between the carbon atoms in the molecule below?

sp/sp3

Using valence bond theory, what is the hybridization of sulfur in SO2?

sp2

Using valence bond theory, what is the hybridization of phosphorus in PO4 3-?

sp3