question_answer 52)

  The spontaneity means, having the potential to proceed without the assistance of external agency. The processes which occur spontaneously are: (a) flow of heat from colder to warmer body (b) gas in a container contracting into one comer (c) gas expanding to fill the available volume (d) burning carbon in oxygen to give carbon dioxide

Answer:

  (c, d) Gas expands or diffuses in available space spontaneously, e.g., leakage of cooking gas gives smell of ethyl mercapton spontaneously. Moreover, burning of carbon to \[C{{O}_{2}}\] is also spontaneous.