Explain why caffeine can be extracted from the tea leaves into hot water and how you extracted the aqueous solution and isolated the crude caffeine.

The hot water dissolves the flavor and color components.

Explanation:

Caffeine can be extracted from the tea leaves into hot water because the hot water dissolves the flavor and color components away from the solid vegetable. This is an example of a solid-liquid extraction. We can extracted the aqueous solution and isolated the crude caffeine by converting the components of caffeine into their calcium salts which are insoluble in water. Then the caffeine can be extracted from the water by using methylene chloride.

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.