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Hi. so apparently I am reviewing for my exams hence it would be better to practice solving on your own.
so i started answering some questions and I got stuck with this problem. the question goes with answer and a "general solution" so I am on the part of deciphering it how does the  solution ended up to such value.problem is, we get different answers on getting delta H: i got -1513.69 btu/lbm, the solution goes with -99 btu/lbm. can someone please help me what have i done wrong?
Thank you very much.