chemistry
posted by lyne on .
Nitrogen (N2) and hydrogen (H2) react to form ammonia (NH3). Consider a mixture of six nitrogen molecules and six hydrogen molecules in a closed container. Assuming the reaction goes to completion, what will the final product mixture be?
number of NH3 molecules
number of N2 molecules
number of H2 molecules
Which of the following equations best represents this reaction?42 N2 + 6 H2 4 NH3
6 N2 + 6 H2 4 NH3 + 4 N2
N + 3 H2 NH3
N2 + 3 H2 2 NH3
N2 + H2 NH3
i know the answers but i have no idea how to do it whih doesnt help. Can someone please explain how to do it?

#1. Write the equation and balance it.
N2 + 3H2 ==> 2NH3
initial concn.
N2 = 6 N2 molecules
H2 = 6 H2 molecules
NH3 = 0 molecules.
If it goes to completion, one of these must be the limiting reagent. How much NH3 would 6 molecules N2 produce? That will be
6 molecules N2 x (2 moles NH3/1 mole N2) = 12 molecules NH3.
How much NH3 would 6 molecules H2 produce?
6 molecules H2 x (2 moles NH3/3 moles H2) = 4 molecules NH3.
The smaller number is 4; therefore, H2 is the limiting reagent and 4 molecules NH3 will be produced. How much N2 will that use.
6 molecules H2 x (1 mole N2/3 moles H2) = 2 molecules N2.
Final mixture:
NH3 = 4 molecules
H2 = 6 molecules to start; we used 6 so we end up with 0 molecules H2.
N2 = We start with 6 molecules, we use 2 molecules N2 so we are left with 62=4.
Check my work. 
If you wrote the balanced chemical equation you know the answer.

okay that makes perfect sense thanks :)