Can you find the absolute value of internal energy?

The absolute value of internal energy of a substance cannot be determined.

Why it is difficult to calculate internal energy?

This internal energy is often very difficult to calculate in real life settings, though, because chemists tend to run their reactions in open flasks and beakers that allow gases to escape to the atmosphere. Therefore, volume is not held constant, and calculating ΔU becomes problematic.

Why is it possible to measure absolute entropies but not absolute enthalpies?

The reason is that the entropies listed are absolute, rather than relative to some arbitrary standard like enthalpy. This is because we know that the substance has zero entropy as a perfect crystal at 0 K; there is no comparable zero for enthalpy.

How is it possible to find the value of Delta U and not the value of you?

ΔU can be calculated in term of ‘W’ and ‘q’ by first law but internal energy (U) cannot be calculated practically by adding for each molecule.

Why absolute zero is not possible?

There’s a catch, though: absolute zero is impossible to reach. The reason has to do with the amount of work necessary to remove heat from a substance, which increases substantially the colder you try to go. To reach zero kelvins, you would require an infinite amount of work.

Why or how it is possible to have an absolute value for the entropy of a system?

Unlike enthalpy or internal energy, it is possible to obtain absolute entropy values by measuring the entropy change that occurs between the reference point of 0 K (corresponding to S=0) and 298 K (Tables T1 and T2). For instance, So for liquid water is 70.0 J/(mol•K), whereas So for water vapor is 188.8 J/(mol•K).

What is the value of E for reversible isothermal evaporation?

For all isothermal processes, ΔE=0.

Can absolute zero freeze the sun?

A. sun contains an enormous amount of energy which can not be created or destroyed only converted. Absolute zero isn’t “a thing” you can just bring to the sun and freeze it with.

Is absolute zero measurable in theory?

At absolute zero enthalpy or heat ceases to exist as a measurable physical quantity. absolute zero is the lowest theoretical possible temperature. This means that absolute zero is the lowest possible measure of motion. Theoretically at absolute zero all motion ceases.

Can absolute value of entropy can be determined?

Unlike enthalpy or internal energy, it is possible to obtain absolute entropy values by measuring the entropy change that occurs between the reference point of 0 K (corresponding to S=0) and 298 K (Tables T1 and T2).

How can we calculate Delta S for an isothermal process?

Write the total differential of the entropy as a function of temperature and volume:

1. dS(T,V)=(∂S∂T)VdT+(∂S∂V)TdV. The constant temperature process, or isothermal process, is the second term, so we seek only: ΔS=∫T2T1(∂S∂T)VdT 0 + ∫V2V1(∂S∂V)TdV.
2. (∂S∂V)T=(∂P∂T)V. So, we have:
3. ΔS(const. T)=∫V2V1(∂P∂T)VdV.

What will be the specific heat of a gas in an isothermal process?

The specific heat of a gas in an adiabatic process is zero but it is infinite in an isothermal process.