Using the equation

N2+3H2-->2NH3

how many grams of NH3 is made if 11 grams of N2 are used?

13.36

first you have to convert the grams of nitrogen into moles when you got the moles of nitrogen. Then 2 moles of ammonia react with 1 mole nitrogen you have doubled the nitrogen mole and then convert the moles into the grams of ammonia.

use this formula for that:

moles = gram/molar mass