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Question
The spontaneity means, having the potential to proceed without the assistance of external agency. The processes which occur spontaneously are:
(i) Flow of heat from colder to warmer body.
(ii) Gas in a container contracting into one corner.
(iii) Gas expanding to fill the available volume.
(iv) Burning carbon in oxygen to give carbon dioxide.
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Solution
(iii) Gas expanding to fill the available volume.
(iv) Burning carbon in oxygen to give carbon dioxide.
Explanation:
Gas expands or diffuses in available space spontaneously, e.g., leakage of cooking gas gives smell of ethyl mercaptan spontaneously. Moreover, burning of carbon to \[\ce{CO2}\] is also spontaneous.
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