Answer:
At 85°C the substance is already in liquid form. Now adding more heat increases the random motion of the constituent molecules of the substance this random motion goes on increasing till the molecules reach to temperature of 140°C where the molecules are enough energetic to leave the surface of liquid hence turning into gas. after that the energy supplied try to increase again the random motion of molecules in gas . This process goes on till the gas molecules reach to temperature of 145°C