1i had given the same answer as integrations......@ nishant...i agree......
when ice melts at 1°...will the enthalpy increase or decrease..,..answer given is enthalpy increases
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62hmm.. cant think of anything right now...
I guess i will have to think more! but i have a few issues with the premise of the question now!!
first look i felt it was a great question...
I guess it still is.. but i will look more into it ...
or may be this is one of those misadventures many of these coaching institutes make a lot of times !!
1arey enthalpy increase kar raha hai .... toh isme kya load hai????
....i thot the ans given is enthalpy decreases (as u posted in chem forum) ..... dats y i was giving diff reasons...
1
1wen ice is meltin we c vapours given out by it
i simply means it absorbs heat as it absorbs heat del H>0 .......wich means enthalphy increases
corrct me if m wrng
1357actually ΔU is zero for ideal gas and isothermal process (when both is true)
here ΔU is not zero
ΔH=mL
also ΔH=ΔU+PΔV≈ΔU (as change in volume is negligible)
so here enthalpy increases
33Sky's other reason in chemistry forum for this question.....
(our sir explained.....)
ΔH = ΔU + PΔV
ΔU=0 since no temp change as ΔU= nCvΔT
bt, del V decresaes in water till 4 degree cel.
so finally,,,, delH decreases.......
62yeah even i was superconfused those days.. (still am) as u can see from my responses..
i liked the physics wala part of thermody.. but chem i was not good at...
basicaly JEE level thermod is very easy and interesting... most of the time..
dont worry about this question.. u have already seen how few ppl know about it among all that u have asked .. right :)
So u need to be able to solve potential JEE questons :)
a few questions here and there dont make u bad at any subject.. there are so many unsolvable questions that i can put just to overwhelm.. or anyone else could.. but The point of studying is not that :)
1im confused with the thermodynamics in physics and chemistry.....both are opposite,,,,this is a physics question/....
1ΔH = ΔU + PΔV
with inc in temperature ΔU increases...
but in water, ΔV decreases till 4°C....
so may be, decrease of ΔV > increase of int energy...
so, overall effect is decrease in enthalpy...
1the question was...
when ice melts at 1°C...
a)enthalpy increases b)enthalpy decreases
62what does this mean??
I mean ice melts at 0 degree...
melting at one degree could mean that we have put ice under conditions such that it has different pressure...
62hmm..
Doubt:
is it ice at 1 degree
or
is it ice at 0 degree and outside temp at 1 degree?
1why are u saying thatΔG is zero....why can't it be less than zero???
62i see there is a flaw in sky's solution..
that is bcos ΔU is not 0
I have a solution..
ΔH=TΔS
Now randomness increases.. cos we are going from solid to liquid state.
So ΔS increases.
So ΔH increases...
I guess this is a good question.. we should discuss more on this one...
1but for ice to melt....it should take in heat,,....its an endothermic reaction...so will not enthalpy increase???
1enthalpy is nothin but stream of impropernes
so increase in it is
wat v can call is tendency oppppppsing stability
so wen heated ice
it xpandzzz so molecules move away awayyyyyyyyyy fm
eachother due 2 thermal zpannsioin
so it ie enthalpy shod increaaaaaaaaaaaaaaaaaaaaaase