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Orgo ch 3
Question | Answer |
---|---|
Where does bonding occur? | In the outermost electron shell of atoms |
What do the quantum numbers n, l, and m describe? | The size, shape, and number of atomic orbitals an element possesses. |
What is a molecular orbital? | They occur when two atomic orbitals combine |
What is the difference between a bonding orbital and an antibonding orbital? | Bonding orbitals are produced when the signs of the wave functions of the 2 combining molecular orbitals are the same, and it is lower-energy, i.e. more stable. An antibonding orbital happens when the signs are different; it is higher-energy, less stable. |
What is a sigma bond? | A single bond |
What is a pi bond? | It forms when two p-orbitals line up in a parallel fashion, their electron clouds overlap and a bonding molecular orbital is formed. A pi bond on top of an existing single bond is a double bond. A sigma bond and two pi-bonds is a triple bond. |
Are pi bonds stronger than sigma bond? | No. Pi bonds are weaker, but double and triple bonds are stronger than single bonds. |
What is the electron configuration of carbon? | 1s2 2s2 2p2 |
How many electrons does carbon need to complete its octet? | 4 |
What are hybrid orbitals? | They are formed by mixing different types of orbitals, using math. 3 p-orbitals and 1 s-orbitals combine to form 4 newly shaped, identical sp3 orbitals. |
Describe the shape of sp3 orbitals. | The 4 orbitals point toward the vertices of a tetrahedron to minimize repulsion. |
How is hybridization accomplished? | By promoting one of the 2s electrons into the 2p-z orbital. This produces four valence orbitals, each with one electron, which can be mathematically mixed to provide hybrids. Hybridization is a way of making all of the bonds to a central atom equivalent. |
What is an sp2 orbital? | The hybrid of 1 s-orbital and 2 p-orbitals. 3 hybrid orbitals are formed. |
What kind of bonds are sp2 orbitals seen in? | Alkenes |
What is the s character of sp2 hybrid orbitals? | 33%. The p percent is 66 percent. |
What is the degree of separation between sp2 orbitals? | 120 degrees |
How do orbitals in ethylene line up? | The sp2 hybrids will participate in CH single bonds, the other hybrid orbital will line up with the unhybridized p-orbital, forming the single and double bonds in C=C |
How are triple bonds formed and what hybrids are involved? | 2 p-orbitals form pi bonds. The 3rd p-orbital combines with s to form 2 sp hybrids oriented 180 degrees apart. |