I asked this question yesterday and it was answered, but I still have a question on it.

Standard entropies for substances are defined at a pressure of exactly 1 bar in some books or exactly 1 atm(760 torr) in different books. For gases, this correction factor would be..... in J/molK? (Answer must be exact to 6 sig figs)

Answer is in format 0.xxxxxx (the x's are numbers)

What does it means by correction factor?

The answers I was provided by bobpursley were not in J/mol*K... instead they were just conversions... is that what the question is asking?

The question above further asked if this would apply to solids and liquids, and the answer is 'no'.

Thanks

No, the question is looking for how pressure affects entropy. For free energy,

g' =go</sub) + RT ln P' where P' is the change in pressure (ratio).

If you divide g' by T, that is entropy, so the change in Entropy will be R lnP'.

You need to confirm this...it has been a long time.

The correction factor mentioned in the question refers to the adjustment needed for the standard entropy values of gases depending on the pressure unit used. Different sources may define standard entropies for substances at different reference pressures, either 1 bar or 1 atm (760 torr).

To answer the question correctly, we need to calculate the correction factor for the change in entropy due to the pressure difference.

The equation provided by bobpursley, g' = g_o + RT ln P', helps us determine the change in standard free energy, where g' is the free energy at the new pressure, g_o is the standard free energy, R is the ideal gas constant, T is the temperature, and P' is the new pressure.

If we divide both sides of the equation by T, we get:

g' / T = g_o / T + R ln P'

The left-hand side represents the change in entropy, ΔS = g' / T, and the right-hand side can also be written as ΔS_o + R ln P', where ΔS_o is the standard entropy.

Therefore, the change in entropy is determined by the term R ln P', which represents the correction factor for the pressure difference.

Now, to answer the specific question regarding gases, the correction factor for the change in entropy is R ln P', where R is the ideal gas constant (8.314 J/mol*K). However, since the question asks for the answer in six significant figures, we need to use the exact value of R, which is 8.3144621 J/mol*K.

Therefore, the correction factor for gases is 8.3144621 ln P', where P' is the pressure ratio. You need to input the specific pressure ratio to get the exact value of the correction factor in J/mol*K.

Regarding the last part of your question, whether this correction factor applies to solids and liquids, the answer is no. The correction factor discussed above is only applicable to gases. The standard entropies of solids and liquids are generally defined at the reference temperature and pressure (298 K and 1 bar or 1 atm).