PArtial pressure= concentration?

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Meachelle_Lum_1I
Posts: 92
Joined: Fri Sep 28, 2018 12:24 am

PArtial pressure= concentration?

Postby Meachelle_Lum_1I » Thu Jan 10, 2019 1:39 am

When asked to find the partial pressure of a gas, is this the same thing as finding the equilibrium concentration?

If so, then why is Partial Pressure = conc (RT) ?

Isn't that equation saying that partial pressure = concentration * R * T not that partial pressure = concentration?

ThomasLai1D
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

Re: PArtial pressure= concentration?

Postby ThomasLai1D » Thu Jan 10, 2019 9:19 am

While not equivalent, both partial pressures and concentration are used in calculating K. The equation P=(conc)(RT) allows you to convert between the two. With respect to solving for the partial pressure, you would use the same algebra to calculate the pressures and concentrations (For partial pressures K=(PProducts)^b / (PReactants)^a or for concentrations K=[Products]^b / [Reactants]^a)

Olivia Young 1A
Posts: 60
Joined: Fri Sep 28, 2018 12:24 am

Re: PArtial pressure= concentration?

Postby Olivia Young 1A » Thu Jan 10, 2019 10:51 am

The partial pressure of a gas is not the same thing as finding the equilibrium concentration, but they are related. Partial pressure = (concentration)*R*T because it is derived from the ideal gas law, PV=nRT. When solving for pressure, P, you divide both sides by V, volume, and n/V equates to concentration. Therefore, the concentration multiplied by the gas constant, R, and temperature, T, is equal to partial pressure. Partial pressure is used to calculate Kp, while Kc is calculated using the concentrations.


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