Jan baptista van helmont did an important experiment related to photosynthesis. he weighed a small willow tree and a pot of soil. jan then planted the tree in the pot. over the course of five years, he added only water to the pot. at the end of five years, he weighed the tree and found that it had gained 74.4 kg. he weighed the soil, and it was only 57 g less. what do the results of this specific experiment demonstrate about what is needed for a plant to grow and increase its mass?

Explanation:

This experiment demonstrate that a plant don't need only water to grow and increase its mass.

A plant will also need nutrients located in the soil that will help it grow and increase its mass.

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.

dynamic equilibrium is the answer.