Cyclohexane (C) and methylcyclopentane (M) are isomers with the chemical formula C₆H₁₂. The equilibrium constant for the rearrangement C ⇌ M in solution is 0.140 at 25°C. 

(a) A solution of 0.0200 mol · L^–1 cyclohexane and 0.100 mol · L^–1 methylcyclopentane is prepared. Is the system at equilibrium? If not, will it form more reactants or more products? 

(b) What are the concentrations of cyclohexane and methylcyclopentane at equilibrium? 

(c) If the temperature is raised to 50°C, the concentration of cyclohexane becomes 0.100 mol · L^–1 when equilibrium is re-established. Calculate the new equilibrium constant. 

(d) Is the reaction exothermic or endothermic at 25°C? Explain your conclusion.