H-H bond’s energy=436 kj
Cl-Cl bond’s energy=242 kj

o total energy on reactants side= 436+242

=678 kj

similarly,

H-Cl bond’s energy=431 kj

so total enery on products side =2 x 431

=862 kj

so by the formula del H rteactants-del H products

678-862= -184 and “-” sign indicates an exothermic reaction as total energy of bond forming is greater than total energy of bond breaking………….. am i corect??????????

Well done. Your answer is correct and i like the way you present it.

Examiners marking your exam papers will be equally happy to see it too.

PS: Just note that units “kj/mol” need to be reflected at your final answer of “-184 kj/mol”. If not marks will be taken away. It seems like you made the same error like Gary. Rmbr to reflect the units when showing your final answer/working.

Hope this helps.

Cheers
Sean
Master Trainer
Author

Well done. Your answer is correct and i like the way you present it.

Examiners marking your exam papers will be equally happy to see it too.

PS: Just note that units “kj/mol” need to be reflected at your final answer of “-184 kj/mol”. If not marks will be taken away.

Hope this helps.

Cheers
Sean
Master Trainer
Author

Yes. You are absolutely spot on.

It is indeed an Exothermic Rxns.

Might be better if you show the proper working step by step in Chemistry Exams.

Examiners are looking for the word “Overall Heat Change” in the chemical reaction is “-184 kj/mol”.

Hope this is clear
Sean
Master Trainer
Author

PS: Keep up the good work.