At what rate of sublimation and deposition there is in the ice 173 K set at a room temperature?

Question

A sample of dry ice (solid CO2) is cooled to 173 K and is set on a table at room temperature. At what temperature is the rate of sublimation and deposition the same? (ASSUME THAT THE PRESSURE IS AT 1 ATM).

Answer 1

Sublimation is the process of going from a solid to a gas without going through the liquid phase.  Deposition is the opposite process.  The temperature at which these processes occur at 1 atm pressure is 194.65 K.

Answer 2

The temperature at which the rate of sublimation and deposition are the same is the temperature at which these two processes are in equilibrium (this temperature is the freezing point, or sublimation point of CO₂). For CO₂ at 1 atm this is about 195 K. This question is like asking at what temperature water freezes in that-- since the pressure is standard 1 atm-- you can readily look up the answer in a data table.