1. True or False. The arrow labeled C represents a transfer of chemical energy to mechanical energy. Explain why this is true or false. 2. True or False. The arrow labeled A represents a transfer of solar energy to chemical energy. Explain why this is true or false.

3. Which arrow or arrows represent a release of carbon dioxide? What process is occurring at the arrow(s) you selected?

4. Which arrow or arrows indicate a process that cycles carbon from living or nonliving organisms? Describe the process or processes you selected.

5. Which arrow or arrows represent reactions that demonstrate a conservation of mass and energy? Explain your answer.

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.

i think it's letter a.