Draw the two chair conformers for each of the following and indicate which conformer is more stable:
a)cis-1-ethyl-3-methylcyclohexane
b)trans-1-ethyl-2-methylcyclohexane
c)trans-1-ethyl-2-isopropylcyclohexane
d)cis-1,2-diethylcyclohexane
e)cis-1-ethyl-3-isopropylcyclohexane
ecis-1-ethyl-4-isopropylcyclohexane