The process of occurs when a hydrate loses its water of hydration.
a. effloresce
b. hydration
c. deliquescent
d. solvation

Let us understand all the terms

Hydration : this is the addition of water to anything. It can be addition of water to double or triple bond, absorption of water by a substance. so it cannot be loss of water.

Deliquescent : it is the absorption of water by a substance and getting dissolved in it. Like NaOH is a deliquescent substance.

Solvation: It is the phenomenon where a substance get surrounded by solvent molecules. If solvent is water it is known as hydration.

Thus the answer is

effloresce : where a substance loses water.

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.