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## Main Question or Discussion Point

Hello all! You know, I thought I knew something about ideal gas mixtures, but now I am not so sure. I am reading through a section of a text that discusses the

[tex]\frac{p_i}{p} = \frac{n_iRT/V}{nRT/V} = \frac{n_i}{n} = y_i \qquad(1)[/tex]

[tex]\frac{V_i}{V} = \frac{n_iRT/P_i}{nRT/P} = \frac{n_i}{n} = y_i \qquad(2)[/tex]

Now the 2 models just described are based on 2 different assumptions and it would seem as though the 2 assumptions are conflicting with each other. That is, since the Dalton model

This would suggest that if I am doing calculations with an ideal gas mixture, I can only talk about partial pressures OR partial volumes and not both.

Does this make sense to anyone? I would like to clarify this because I am doing some experimental work, and I need to converto from an equivalence ratio to a percent volume and that is how all of this confusion started.

*Dalton*and the*Agamat*models of ideal gas*mixtures*. I will briefly describe each:__: The underlying assumption is that each mixture component behaves as an ideal gas as if it were__**Dalton Model***alone at the temperature T and volume V of the mixture*. Hence, can apply the ideal gas relation to both the mixture and each component to arrive at[tex]\frac{p_i}{p} = \frac{n_iRT/V}{nRT/V} = \frac{n_i}{n} = y_i \qquad(1)[/tex]

**: The underling assumption is that each mixture component behaves as an ideal gas as if it**__Agamat Mode__*existed separately at the pressure P and temperature T of the mixture*. Hence,[tex]\frac{V_i}{V} = \frac{n_iRT/P_i}{nRT/P} = \frac{n_i}{n} = y_i \qquad(2)[/tex]

Now the 2 models just described are based on 2 different assumptions and it would seem as though the 2 assumptions are conflicting with each other. That is, since the Dalton model

*assumes*common T and V, it*gives rise to*the concept of a partial pressure. And again, since the Agamat model*assumes*common T and P, it*gives rise to*the concept of partial volumes.This would suggest that if I am doing calculations with an ideal gas mixture, I can only talk about partial pressures OR partial volumes and not both.

Does this make sense to anyone? I would like to clarify this because I am doing some experimental work, and I need to converto from an equivalence ratio to a percent volume and that is how all of this confusion started.