What can be said about a substance with a triple point above 1atm
1) The liquid state of the substance cannot exist.
2) The gaseous state at 1 atm pressure cannot be condensed to the solid at the triple point temperature.
3) The melting point of the solid must be greater than 0 C.
4) The liquid state cannot be maintained in a beaker open to air at 1 atm pressure.
5) The melting point and boiling point of the substance are identical.
6) The solid and liquid states of the substance cannot coexist at equilibrium.
I know triple point is when solid, liquid, and gas coexist. However, what is special about that if the pressure is higher than 1atm? I was thinking 2) because I found online that "Triple point lies above 1 atm, implying that
liquid CO2 cannot exist at normal
pressures"
1 answer
but I'm not sure if that's correct.