. Iron filings and sulphur were mixed together and divided into two parts, ‘A’ and ‘B’. Part ‘A’ was

Iron  filings and sulphur were mixed  together  and divided  into  two parts, ‘A’ and ‘B’. Part ‘A’ was heated strongly while Part ‘B’ was not heated. Dilute hydrochloric acid was added to both  the Parts and evolution of gas was seen in both the cases. How will you identify the gases evolved