Q. 12.5.2

Answer the following questions based on the phase diagram (not drawn to scale) for ammonia, NH$_{3}$.
a. What is the normal melting point? The normal boiling point?
b. At what temperature and pressure do the three phases coexist in equilibrium?
c. Is ammonia a solid, a liquid, or a gas at room temperature and pressure? If a gas, is it a permanent gas?
d. Which is the more dense phase, the liquid or the solid?