properties of alkanes Flashcards
1
Q
what is the alkanes general formula
A
CnH2n+2
2
Q
how is a sigma bond formed in alkanes
A
the overlap of orbitals directly between the bonding atoms
3
Q
how do sigma bonds rotate
A
freely
4
Q
what is the shape and bond angle of alkanes
A
each carbon is surrounded by 4 bonded pairs of electrons. these all repel as far as possible, resulting in a tetrahedral shape and a bond angle of 109.5
5
Q
what is the trend in boiling points of straight chain alkanes and why
A
as carbon chain length increases boiling point increases
as there are: more electrons, more points of contact between atoms, strength of London forces between molecules increases and more energy is needed to break the IMFs
