1) An ideal gas is taken through a process such that when the volume is halved the temperaure gets doubled .Prove that change in entropy is given by Cp *ln2.
2) When an egg is boiled the yolk and the albumin get solidified; so shouldn't the entropy decrease? But it increases. How?
3) Work done in a reversible process is slightly more than work done in an irriversible process. Why?
3. Consider an expansion taking place with pressure falling from 10 atm to 1 atm. Imagine p-V axes as y-x axes. In one case as the gas is taken from 10 atm to 1 atm, the external ressure is adjusted so that it is in equilibrium with the gas pressure (strictly speaking, gas pressure has to be slightly higher for expansion to take place). When you draw this type of process, you get a smooth falling curve. Now consider the second case where 10 atm is brought to 1 atm external pressure almost immediately. In this case, unlike the previous case where pressure gradually falls from 10 atm to 1 atm (that is 10 to 9.9999 to 9.9998...........1) pressure is flat at 1 atm. Imagine a line y=1 in this case on the p-V graph. For the same change in volume it can be seen clearly which area would be more. I do not think that this difference is always, "slight". It can be pretty significant sometimes. While is science, normally there is a lot of mention of reversible processes, the real processes are always irreversible.
2. It is not clear if the assertion saying the entropy decreases is referring to the entropy of the system or the entropy of the universe.
1. \(dS=\frac {dq}{T}\)
\(\Rightarrow dS=\frac {nC_vdT+pdV}{T}\)
\(\Rightarrow dS=\frac {nC_vdT}{T}+\frac{pdV}{T}\)
\(\Rightarrow dS=\frac {nC_vdT}{T}+\frac{nRdV}{V}\)
\(\Rightarrow \Delta S=\int\limits_{T_i}^{T_f} {\frac {nC_vdT}{T}}+\int\limits_{V_i}^{V_f}{\frac{nRdV}{V}}\)
One can proceed further from here.....
Sir, part 2 is for the entropy of the "system".That is the egg.
PS: Has it to do with the denaturation of proteins in the egg??
PS: Has it to do with the denaturation of proteins in the egg??