Why does a room containing oranges acquire their aroma

Why does a room containing oranges acquire their aroma  

When a bowl containing fresh oranges is placed on the dining room table, the room acquires their fragrance within a few hours. The organic substance we smell after its release from the oranges is the organic terpene (+)-limonene (I), each molecule of which is small and relatively non-polar. I readily evaporates at room temperature to form a vapour. 

The process we detect when we note the intensifying smell of the oranges, is  

We could obtain this result more rigorously. We have met the symbol A several times already, and recall its definition final state minus initial state , so the change in entropy AS for any process is given by the simple equation 

If the final disorder of a spontaneous process is greater than the initial disorder, then we appreciate from Equation (4.2) how a spontaneous process is accompanied by AS of positive sign. This will remain our working definition of spontaneity. 

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