CHEM 2443 Lecture Notes - Lecture 5: Prestressed Concrete, Chlorine, Vsepr Theory

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12 Aug 2016

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Slide 6: filled p orbital lower energy than unfilled p orbital. Slide 7: ch4 = tetrahedral, solid wedge line = coming toward you, dashed line = going away from you. Slide 8: lcao model does not show that ch4"s bonds are exactly the same, but they are. Slide 9: all 4 of the 4 electrons that form the 4 bonds have to be the same energy (same orbital) Not possible, we have to move things around: lcao model predicated upon the idea that 2 atoms are coming together to make a molecule. Electron promotion (only a model used for lcao) Slide 10: electron density pointed toward the atoms in hybrids. Slide 11: 1 electron from 2s, 2 electrons from 3 degenerate 2p orbitals, mix together, we get 4 hybrids in the new hybrid sp3 orbital, 1 s and 3 p electrons = sp3.

Related Questions

Benzene is an organic chemical compound with the molecular formula C6H6. In the benzene molecule, carbon atoms form a ring with alternating single and double bonds connecting them. Thus, each individual carbon atom forms one ? bond with another carbon atom and one ? and one ? bond with another carbon atom. Each carbon atom also forms one ? bond with a hydrogen atom. Identify which types of orbitals overlap to form the bonds between the atoms in a benzene molecule. Drag the appropriate labels to their respective targets.

Attached is picture. Please explain/show work, will give 5 stars to correct answer, thank you very much! :)

Chemical bonds are formed by linear combinations of atomic orbital's. These atomic orbital's should have compatible energies. An axial overlap of these orbitals results in the formation of a sigma bond, whereas a lateral overlap results in the formation of a pi bond. When two atomic orbitai's on different atoms approach each other, two molecular orbital's are formed: one bonding molecular orbital and one antibonding molecular orbital. The bonding molecular orbital has a lower energy than the corresponding atomic orbital's: antibonding orbital's have higher energies than the corresponding atomic orbital's. An example using the hydrogen molecule is shown here. However, the same rule applies to systems with multiple atomic orbital's. For each atomic orbital that overlaps, one molecular orbital must form. In the diagram below. 1s orbitais from two hydrogen atoms combine to form one bonding sigma1 orbital and one antibonding orbital. The total number of bonding and antibonding orbital's is always equal to the number of orbital's that overlap. Similarly, molecular orbital's can also be formed by the overlapping of hybrid orbital's. The hybrid orbital's are formed by the linear combination of different atomic orbital's of nearly equal energy on the same atom. The atomic orbital's of nearly equal energy undergo a process of mixing and reorientation to form new orbital's of lower energy. This process is called hybridization For example, hybridization of one s and two p orbital's on an atom forms three sp2 hybrid orbital's. Benzene is an organic chemical compound with the molecular formula C6H6. In the benzene molecule, carbon atoms form a ring with alternating single and double bonds connecting them. Thus, each individual carbon atom forms one sigma bond with another carbon atom and one sigma and one pi bond with another carbon atom. Each carbon atom also forms one sigma bond with a hydrogen atom. Identify which types of orbital's overlap to form the bonds between the atoms in a benzene molecule.

Which of the following does not have a more stable resonance structure?

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Question 21 pts

In the following molecule, which carbons are electron deficient, meaning they hold a partial positive charge (Î´+) in the hybrid structure. All carbon atoms are identified by a number.

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Question 31 pts

Rank the following resonance structures from most to least stable.

III (most stable) > I > II (least stable)

III (most stable) > II > I (least stable)

I (most stable) > II > III (least stable)

II (most stable) > III > I (least stable)

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Question 41 pts

Which of the following accurately depicts a Lewis acid-base reaction where a carbon is acting as the Lewis acid and an oxygen is acting as the Lewis base.

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Question 51 pts

Which of the following statements about Lewis acids and bases is true?

A Lewis base always accepts an electron pair from a Lewis acid.

The interaction between a Lewis acid and a Lewis base creates a covalent bond.

Lewis acids are also commonly called nucleophiles.

A Lewis base always accepts a proton (H+) from a Lewis acid.

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Question 61 pts

A molecular orbital energy diagram was created that contains two bonding orbitals and two antibonding orbitals. How many atomic orbitals were mixed to create all these orbitals?

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Question 71 pts

Which of the following statements about the molecular orbital diagram for H2â is false?

Two atomic orbitals combine to produce two molecular orbitals.

There is one filled bonding orbital.

There is one empty antibonding orbital.

There is a non-zero bond order.

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Question 81 pts

If a p atomic orbital and an s atomic orbital were to interact and combine to create new molecular orbitals, how many antibonding molecular orbitals would be created?