Absolute zero is the point at which...

Question

A. a straight-line graph of V versus T(K) intersects the origin.

B. a straight-line graph of V versus T(°C) intersects the origin.

C. gaseous helium liquefies.

D. a straight-line graph of 1/V versus P at constant T intersects the origin.

E. a straight-line graph of V versus 1/P at constant T intersects the origin.

So far I have gotten this question wrong twice. I don't understand what the graph is.

Answer 1

The answer is A. When you plot the volume (or the pressure) of a gas versus temperature in Kelvins, the line should go to zero V (or P) when T = 0° K, i.e., at the origin. Absolute zero was found by plotting °C on the x-axis and finding that extrapolation of the line fitting V (or P) vs temperature intersected the x-axis at -273 °C.

Answer 2

The answer is A. When you plot the volume (or the pressure) of a gas versus temperature in Kelvins, the line should go to zero V (or P) when T = 0° K, i.e., at the origin. Absolute zero was found by plotting °C on the x-axis and finding that extrapolation of the line fitting V (or P) vs temperature intersected the x-axis at -273 °C.