Question

A) How many grams of H2H2 are needed to produce 10.99 g of NH3?

Express your answer numerically in grams.

B) How many molecules (not moles) of NH3 are produced from 8.84×10−4 g of H2?

Express your answer numerically as the number of molecules.

Answer 1

A.
N2 + 3H2 ----------------- 2 NH3 so 3 moles of H2 are required to produce 2 moles of ammonia. so the molar ratio is 3:2.

10.99 grams of NH3 = 0.6465 moles so

3H2/2NH3 = x/0.6465,

X = 0.9697 moles
0.9697 moles X 2 grams/mole = 1.9395 grams of H2
3 moles = 6 grams of H2 produce 2 moles = 34 grams NH3
so 6/34 = X/10.99 = 1.94 grams

B.

First you need to collect the weights for a balanced reaction,

MW = 2, 28, and 17 for H2, N2, and NH3 so 3 moles hydrogen weighs 6 g, 1 mole nitrogen is 28 g, and 2 moles ammonia is 34 g.

As above 6/34 = z/(8.84x10-4) z = 1.559x10-4 grams are produced, which is (1.559x10-4)/17 = 9.1705x10-6 moles. Multiply by 6.022141x10^23 molecules/mole to get

5.0642x10^19 molecules

Hope this will help you. For any question regarding my answer, write me in comment.

If satisfied with answer, please leave positive feedback. Thanks.