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Q.
Least stable conformer of cyclohexane is
J & K CETJ & K CET 2008Hydrocarbons
Solution:
Planar hexagon conformer has considerable angle strain due to the fact that its bonds are not $109.5^{\circ}. $ It also has torsional strain. Due to presence of these strains planar hexagon conformer of cyclohexane is least stable.