how will you show that lodline is a sublimable substance . explain with the help diagram
Answers
Answer:
When the temperature gets to 113.7 oC (point 2), the temperature stops rising as the added heat is used to melt solid iodine. ... When vaporization is complete, the temperature again begins rising. In this system, we see iodine vapour only when the temperature is at 184.3 oC or higher.
Answer:
I think your question can be more generally stated, and subsequently, answered. Why do some substances sublime, while others don't?
To understand this, you need to understand a phase change to gas occurs when the total vapor pressure of substance in a condensed phase (solid or liquid) exceeds the atmospheric pressure.
[In case you aren't familiar with the term, vapor pressure is defined as as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system]
So, at a given temperature, if the atmospheric pressure is low enough, any substance will go from solid to gas (i.e sublime), without having a chance to melt (so to speak).
To gain a better understanding of this process, I urge you to look at a phase diagram. (this particular one is for carbon dioxide, easier to find than iodine's the principal remains the same.)at atmospheric conditions (~1 bar) you can observer solid carbon dioxide goes to gas, bypassing the liquid state. But say, at a higher pressure say >10 bar, it does indeed go from solid to liquid to gas, as it is warmed.
