To understand reaction order and rate constants. for the general equation aa+bb→cc+dd, the rate law is expressed as follows: rate=k[a]m[b]n where m and n indicate the order of the reaction with respect to each reactant and must be determined experimentally and k is the rate constant, which is specific to each reaction.
a. what is the overall reaction order?
b. what are the units of the rate constant k for this reaction?
c. what would happen to the rate if [br2] were doubled?
d. what would happen to the rate if [no] were doubled?

A. m+n

B. M/s

C. m will be 2

D. n will be 2

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.

just did the assignment and the answer was #1 +2 n