- #1
nikdandeker
- 3
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hi!
Just gave a chem obj. type exam recently. I am confused about one question on thermodynamics.was hopin some1 could throw light on this problem.
the question goes hence-
An exothermic reaction takes place in an adiabatic process.what will happen to the temp of the system?
A)the temp will increase
B)the temp will decrease
C)it will remain constant.
D)any of the above.
so now i wrote d answer as D.but the correct answer it seems was given as "A".
my thought process behind it was that- the exothermic reaction "injects" a FIXED amount of energy into d system.now since an Adiabatic process is taking place, we start with internal energy = "injected" energy plus d amount of internal energy that d system already possessd bfore d commencement of d reaction.
now since an adiabatic process is taking place, work may be done on d expense of internal energy.if the work done(BY THE SYSTEM) is equal to the energy given by the reaction, the internal energy(and hence the temperature) will remain as it was bfore.now on the other hand, had the SYSTEM done work greater than that given by the reaction, some amount of the INITIAL internal energy would have gotten used up.and hence, the temperature of the system would have decreased.lastly, had no work been done, or had d SURROUNDINGS done work on d system, d temp would have increased.
can pls any1 comment on whether my logic is correct? or is A the correct answer?
any help would be sincerely appreciated
Thanking u
Nikhil
Just gave a chem obj. type exam recently. I am confused about one question on thermodynamics.was hopin some1 could throw light on this problem.
the question goes hence-
An exothermic reaction takes place in an adiabatic process.what will happen to the temp of the system?
A)the temp will increase
B)the temp will decrease
C)it will remain constant.
D)any of the above.
so now i wrote d answer as D.but the correct answer it seems was given as "A".
my thought process behind it was that- the exothermic reaction "injects" a FIXED amount of energy into d system.now since an Adiabatic process is taking place, we start with internal energy = "injected" energy plus d amount of internal energy that d system already possessd bfore d commencement of d reaction.
now since an adiabatic process is taking place, work may be done on d expense of internal energy.if the work done(BY THE SYSTEM) is equal to the energy given by the reaction, the internal energy(and hence the temperature) will remain as it was bfore.now on the other hand, had the SYSTEM done work greater than that given by the reaction, some amount of the INITIAL internal energy would have gotten used up.and hence, the temperature of the system would have decreased.lastly, had no work been done, or had d SURROUNDINGS done work on d system, d temp would have increased.
can pls any1 comment on whether my logic is correct? or is A the correct answer?
any help would be sincerely appreciated
Thanking u
Nikhil