In regards to the given question, option “1” is the correct
option. When propane is burnt to complete combustion, it results in the
formation of two completely different substances. It actually forms a mixture
of water vapour and carbon dioxide. When NaCl or sodium chloride is melted, it
does not result in the formation of any new substance and so option “2” cannot
be the correct answer. With regards to deposition of carbon dioxide and solidification
of water, no new substance gets formed and so can be neglected as the answer to
the question.
