maximum mass in grams of NH3

[mybrohshi5]

what is the maximum mass in grams of NH3 that can be produced by the reaction of 1.0 g of N2 and 3.0 g of H2 via the equation below?

N2 (g) + H2 (g) --> NH3 (g) (not balanced)

so first i balanced the equation and got
N2 (g) + 3H2 (g) --> 2NH3 (g)

so the answer is 1.2 g but i have no idea how to get that.

can someone please show me how to get that answer?

thank you

chad

[Russ]

This is a stoichiometry problem, so the first thing to do is calculate the number of moles of each reactant.

n(N2) = 1/28 = .0357
n(H2) = 3/2 = 1.5

From this we can see that (even after the ratio of 3:1 is applied) there is much less N2 than H2. This makes N2 the Limiting Reagant (there's not enough N2 to react with all the H2).

n(NH3) = .0357 * 2 = .0714 (stoichiometric ratio)
m(NH3) = .0714 * 17 = 1.21 (Mass = number of moles * Formula mass)

[mybrohshi5]

thank you =)

that helped a lot.