If 56 grams of notrogen are used up by the reaction, how many grams of amonia will be produced? 1N2+3H2--> 2NH3

1 mole of N2 produces 2 moles of NH3

OR ...

14 x 2 grams of N2 produces 2 (14 + 3) grams of NH3

1 gram of N2 produces 34/28 grams of NH3

therefore, 56 grams produce (34/28) x 56 = 68 grams of NH3

the answer thus would be 68 grams of NH3