Recent content by RedCliff

Hello, Thank you for your replying! I fully agree with you on this point. If we express dU with all state functions, that is, dU = TdS - pdV, yes, your derivation is correct. But my question is: what part is wrong in my above derivation as I use dU = -pdV + CdT? However, you post might...

Agree with Chestermiller, dU = TdS-pdV is nothing to do with the process, (reversible or irreversible), even though it is developed from the reversible process, since all of the qualities here are state functions. Therefore, they are just related to the state.

In thermodynamics, the internal energy (U) is the function of the volume (V) and temperature (T), U = U (T). Therefore, according to the mathematics, dU = π dV + Cv dT, where π is internal pressure and Cv is the constant volume heat capacity. Meanwhile, according to the 1st law, dU = δ w + δq...

Hello, fzero, Thank you very much! I got it now! John

Hello, Bill, You pointed out that <KE> = 3/2 kT is not the definition of the temperature, but the derived result from classical mechanics. However, what is the strict definition of temperature . I seemly read a post from a web saying that "absolute temperature (T) is the indicator of...

Hello, Tom and all, Can you guys answer my question in the last post? That is, why only px, py, pz orbitals are used in LCAO-MO theory? Thanks! John

Hello, Tom, Thanks for your posting and explanation! Your answers clear this basic question held in my mind for a long time! As I read the Atkins' textbook, "physical chemistry", in one place, it says wave functions contain all information on a particle, and in another place, it says px...

"But ψ*ψ is the probability density! What does that have anything to do with anything? It is not even something one measures!" The contour of equal ψ*ψ is used to define the shape of the orbitals. Check the same book and other quantum books (but I am not sure if they make it so clear as that...

"Donut shape? p-orbitals? Where?" Yes, if you plot contour of ψ*ψ of p+1 and p-1, it will give you donut shape. Check Figure 6.13 on pg. 153 in Levine's "Quantum Chemistry" (5th ed). "Not sure where you got the idea that the Schrödinger equation doesn't give you the wave function...

Hello, all, I have a question about the wave functions of H atom: for p orbital, wave functions from the Schrödinger equation are p+1, p0, and p-1. In chemistry, people use the linear combination of p+1 and p-1 to generate px and py orbitals. The question is: p+1 and p-1 orbitals are...