WEBVTT

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Here is the problem: What is the pressure of 0.25 mol of gas in 2 L at 400 K?

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Solve PV equals nRT for P, with pressure in atm, volume in litres, amount in moles and temperature in kelvin.

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Choose the gas constant to match the units. Pressure is in atm and volume in litres.

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Rearrange PV equals nRT for P and substitute.

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So the answer is P equals 4.10287 atm.

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An ideal gas obeys PV equals nRT: pressure times volume is proportional to the amount of gas and its absolute temperature. Real gases follow it closely at low pressure and high temperature.

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PV equals 8.20574 and nRT equals 8.20574, which agree.