5/2R vs 3/2R

[Briana Yik 1H]

how do we know when to use 5/2R versus 3/2R?

[lizettelopez1F]

Cp=5/2r is used when you need to find the heat capacity of an ideal gas with a constant pressure. Cv=3/2R is used when you need to find the heat capacity of an ideal gas with a constant volume

[KatrinaPho_2I]

These values only work if you are dealing with monoatomic ideal gases.

[abbydouglas1K]

If the question says that the pressure is being kept constant(Cp) or that the volume is being kept constant (Cv) you will use 5/2R and 3/2R respectively if the molecule in question is a monatomic gas.

[Christopher Anisi 2K]

For a monoatomic gas under a constant pressure the Cp value is equal to 5/2R however if it is under a constant volume the Cv value is equal to 3/2R.

[Morgan Carrington 2H]

These values only work if you are dealing with monoatomic ideal gases.

What does you mean by a monoatomic gas?

[Claire_Kim_2F]

Monoatomic gases are gases that are noble gases like halogen and other substances.

[John Calonia 1D]

What are the different heat capacities involving R of different types of molecules and is the general rule +1 R for constant pressure.

[Adrienne Chan 1G]

Monoatomic gases are gases that are noble gases like halogen and other substances.

Almost! Monoatomic gases are gases with only one atom, so it would just be noble gases. Halogens are diatomic gases.