Total and Partial Pressure

This page provides insight into determining the total and partial pressure and provides some functions to help you calculate it!
CalculationTotal PressureInputs﻿﻿n (total)
:20.00mol​
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﻿﻿R
:8.31J/mol K​
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﻿﻿T
:25.00K​
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﻿﻿V
:30.00L​
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Here are the variables for the equation
Output﻿﻿P (total)
:138.57atm​
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Ptotal=ntotalRTVP_{total} =\frac {n_{total}RT}{V}Ptotal​=Vntotal​RT​
Partial Pressure CalculationInputs﻿﻿n (of component i)
:500.00mol​
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Outputs﻿﻿P (of component i)
:3,464.17atm​
﻿
﻿
Pi=ninfinal×PtotalP_{i}=\frac{n_{i}}{n_{final}}\times P_{total}Pi​=nfinal​ni​​×Ptotal​
ExplanationPartial pressure is used when a mixture of two or more gases in the same volume expresses the pressure caused by each of the individual gases in the mixture.
The total pressure of the gas mixture is the sum of the partial pressure of the component gases.
The total pressure is an expression of the Ideal Gas Law.
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PV = nRTPV\ =\ nRTPV = nRT
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P=nRTVP =\frac {nRT}{V}P=VnRT​
From here, we can produce the following expressions for total and partial pressure:
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Ptotal=ntotalRTVP_{total} =\frac {n_{total}RT}{V}Ptotal​=Vntotal​RT​
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Pi=niRTVP_{i} =\frac {n_{i}RT}{V}Pi​=Vni​RT​
From this, we can say the partial pressure over total pressure is:
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PiPtotal=niRTVntotalRTV=nintotal\frac{P_{i}}{P_{total}} =\frac{\frac{n_{i}RT}{V}}{\frac{n_{total}RT}{V}}=\frac{n_{i}}{n_{total}}Ptotal​Pi​​=Vntotal​RT​Vni​RT​​=ntotal​ni​​
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∴ Pi=ninfinal×Ptotal\therefore\ P_{i}=\frac{n_{i}}{n_{final}}\times P_{total}∴ Pi​=nfinal​ni​​×Ptotal​
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