organic and instrumental chemistry

what is used instead of VESPR for complex molecules?

molecular orbital theory

what is a molecular orbital?

orbital formed when 2 atomic orbitals combine

what does the combination of 2 atomic orbitals result in?

the formation of a bonding molecular orbital and an antibonding molecular orbital

which molecular orbital has lower energy?

the bonding molecular orbital, this means it fulls first

why does the antibonding molecular orbital exist?

each orbital can only hold 2 electrons but as 2 atomic orbitals combined there must be space for 4 electrons in the molecular orbitals

how is a bond formed?

the attraction between electrons in the bonding orbital to the nuclei of the atoms

what is the position of the molecular orbital in a non-polar covalent bond?

it is symmetrical encompassing both nuclei equally

what is the position of the molecular orbital in a polar bond?

it is asymmetrical with a greater proportion of the orbital over the nuclei with the higher electronegitivity

what is the position of a molecular orbital in an ionic bond

very asymmetrical with the molecular orbital nearly entirely around one nucleiq

what is a sigma (σ) bond?

bond formed by the end on overlap of atomic orbitals to make σ molecular orbitals

what is a pi (π) bond?

a bond formed by the side on overlap of parallel atomic orbitals to form a π molecular orbital

what is hybridisation?

when non-degenerate atomic orbitals combine to form a set of degenerate hybrid orbitals

how can the valency of carbon be explained?

the hybridisation of s and p orbitals

what is an sp³ orbital?

when the s orbital combines with all 3 p orbital to create 4 sp³ orbitals

What organic molecules contain sp³ hybridisation?

alkanes

what type of bond is a carbon-carbon single bond?

σ bond

what type of bond is a carbon-hydrogen bond?

σ bond

what is sp² hybridisation?

when the s orbital combines with 2 of the p orbitals to form 3 sp² orbital leaving 1 hybridised p orbital

what organic molecules is sp² hybridisation present in?

alkenes and benzene/phenyl rings

what type of bond is a carbon-carbon double bond?

σ bond form sp² orbitals and a π bond from the unhybridised p orbitals

what is sp hybridisation?

when the s orbital combines with 1 p orbital to make 2 sp orbitals leaving 2 unhybridised p orbitals

what organic molecules contain sp hybridisation?

alkyenes

how is a carbon-carbon tripple bond formed?

σ bond between sp orbitals and 2 π bonds between hybridised p orbitals

what happens to unhybridised p orbitals in armotaic compounds?

p orbitals overlap to form areas of electron density known as π molecular systems