Phase Diagram The following diagram corresponds to a closed system, comprised of a pure substance. See section 16.11 "Phase Diagrams" in Zumdahl "Chemical Principles" 8th ed., pp 694-699 The letter labels closest to the points marked with a dot refer specifically to those points. The other letter labels refer to the region of the graph in which they lie. Match the following: sublimation occurs -- but no fusion normal gas and/or liquid present at equilibrium -- but no solid normal gas region solid region normal liquid region supercritical fluid region gas, liquid and solid all may be present at equilibrium normal freezing point critical point Take a moment to review your choices above, before submitting! No letter should be chosen more than once.
Which of the following solid substances can be liquefied simply by increasing the pressure suffciently? ice $\left(\mathrm{H}_{2} \mathrm{O}\right)$ dry ice $\left(\mathrm{CO}_{2}\right)$ sulfur $(\mathrm{S})$ diamond (C) graphite (C) There is only one known pure substance which, as a liquid, cannot be frozen by cooling alone at 1 atm pressure. Which is it? water $\left(\mathrm{H}_{2} \mathrm{O}\right)$ helium $(\mathrm{He})$ hydrogen $\left(\mathrm{H}_{2}\right)$ nitrogen $\left(\mathrm{N}_{2}\right)$ mercury $(\mathrm{Hg})$ For the substance represented by the above phase diagram, at any point at which the solid and liquid are in equilibrium, which phase is more dense? liquid solid The pressure at point $\mathbf{F}$ is called the critical pressure. is atmospheric pressure. is called the supercritical pressure