Question #f4c22

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1 Answer
P dilip_k
Aug 20, 2016

Given

#C(gr)+O_2(g)->CO_2(g),DeltaH_1^@=-393.5" kJmol"^-1....(1)#

#CO+1/2O_2(g)->CO_2(g),DeltaH_2^@=-283.0" kJmol"^-1...(2)#

#CO+Cl_2(g)->COCl_2(g),DeltaH_3^@=-108.0" kJmol"^-1...(3)#

#"We are to determine "DeltaH_f^@" of " COCl_2(g)" for the reaction:"#

#C(gr)+1/2O_2(g)+Cl_2(g)->COCl_2(g),DeltaH_f^@=?#

It is obvious that adding(1) and (3) ,then subtracting (2) we can easily get #DeltaH_f^@# of the reaction.

So

#DeltaH_f^@=DeltaH_1^@+DeltaH_3^@-DeltaH_2^@#

#DeltaH_f^@=(-393.5-108.0-(-283.0))" kJmol"^-1#

#=-218.5kJ"mol"^-1#

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