Unit 2 Organic chemistry: Key Area 1 - Molecular Orbitals Flashcards
When atomic orbitals overlap whay do they combine to form?
Molecular Orbitals
Is the molecular orbital is more stable than each of the seperate atomic orbitals?
YES
What contributes to the overall shape of the molecule formed from a molecular orbital?
The increased stability of molecular orbitals compared to the seperate atomic orbitals.
What is the molecular orbital formed a lower energy arrangement than?
The seperate atomic orbitals.
What do molecular orbitals encompass?
Molecular orbitals encompass the whole molecule and are not simply found between atoms inside a molecule.
When is a covalent bond formed?
When the half filled atomic orbitals overlap.
When is a covalent bond known as a sigma bond?
If the two half filled atomic orbitals overlap alon the x axis of the bond.
If half filled atomic orbitals form a sigma bond what type of overlap is this considered to be?
End on overlap.
Can carbon have 4 unpaired electrons?
Through hybridisation by promoting one of the paired 2s orbitals.
What does hydrib theory assume happens to form four degenerate orbitals?
The 2 s and 2p orbitals of carbon atoms combine (or mix).
What are the hybrid orbitals formed from one s orbital and three p orbitals called?
sp3 orbitals
In methane, what are all four hybrid orbitals used to form?
sigma bonds between the central carbon atom and hydrogen atoms.
What do sp3 orbitals form to minimise electron repulsion?
A tetrahedral arrangement.
What does hybridisation give?
3 identical hydrid orbitals.
How does hybridisation in Alkenes work?
Each C atom uses the 2s orbital and only 2 of the 2p orbitals, leaving one 2p orbital unhybridised.
