In an isothermal compression from 4 L to 2 L, what happens to pressure?

You can work it out this way: use PV = constant for an isothermal process.

An isobaric process heats the gas from 300 K to 600 K. How does volume change?

At constant pressure, V is proportional to T.

Which of the four processes does the most work on a PV diagram for the same initial and final states?

You can work it out this way: compare the area under each curve on the PV diagram.

Pro 🔒~30 min

Ideal Gas Law & PV Diagrams

Visualize isothermal, isobaric, isochoric, and adiabatic processes

How it works

An ideal gas obeys PV = nRT, where R = 8.314 J·mol⁻¹K⁻¹. The four standard thermodynamic processes differ in which state variable is held constant: isothermal (T constant, PV = const), isobaric (P constant, V ∝ T), isochoric (V constant, P ∝ T), and adiabatic (no heat exchange, Q = 0). The PV diagram area under each curve equals the work done by the gas.

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Step-by-step

Select a process type with the slider, then adjust temperature or pressure to drive the gas through the process.
Watch the PV diagram update in real time.
Unlock Pro mode to vary the number of moles and compare how different amounts of gas scale the diagram.

Key formulas

$PV = nRT \quad (R = 8.314\,\text{J}\cdot\text{mol}^{-1}\text{K}^{-1})$ Ideal Gas Law
$W = P\Delta V$ Work done in isobaric process
$W = nRT\ln\!\left(\frac{V_2}{V_1}\right)$ Work done in isothermal process
$\Delta U = Q - W$ First Law of Thermodynamics

Frequently asked questions

In an isothermal compression from 4 L to 2 L, what happens to pressure?: You can work it out this way: use PV = constant for an isothermal process.
An isobaric process heats the gas from 300 K to 600 K. How does volume change?: At constant pressure, V is proportional to T.
Which of the four processes does the most work on a PV diagram for the same initial and final states?: You can work it out this way: compare the area under each curve on the PV diagram.