= . Later, the gas is under STP conditions,so T = 273 K and P = 760 mmHg. Now, = .If we set initial = final , we get = . Rearranging and applying some algebra gives us V =
10× × L. This is choice (E).- A Use the phase diagram. At 0.5 atm and 200 K, substance Z is a gas. If we
maintain this temperature and increase the pressure, we can draw a
vertical line from the point (0.5 atm, 200 K). Eventually that vertical line
will cross into the liquid region. This means that, under steadily
increasing pressure, substance Z (starting at 0.5 atm and 200 K) will
condense. Condensation is the phase change from gas to liquid. - C The normal boiling point is the temperature at which the phase change
from liquid to gas occurs, at a pressure of 1 atm. If you extend a
horizontal line from the 1.0 atm mark on the “pressure” axis and see
where it intersects the liquid-gas boundary, you’ll get the normal boiling
point. Doing so on this phase diagram shows a normal boiling point of
about 300 K.