Question #8ea79

1 Answer
Mar 17, 2015

You have three variables, #P#, #V#, and #T#, so you need a three-dimensional graph with #P#, #V#, and #T# axes.

You get a 3D surface that looks like the middle graph in the image below.

Graph of a 3D surface from web.inc.bme.hu.

If the temperature is constant and you look at the graph in a #PV# plane, you see the blue line hyperbola of Boyle's Law, #PV = k#.

If the pressure is constant and you look at the graph in a #VT# plane, you see the straight black line of Charles' Law, #V= kT#.

If the volume is constant and you look at the graph in a #PT# plane, you see the straight red line of Amontons' Law (often called Gay-Lussac's Law), #P= kT#.

Put them all together, and the 3D surface is a graph of the Combined Gas Law, #(PV)/T = k#.