Answer:
0.6425 moles of
is required to react with 25.7 grams of
.
Explanation:
mas of oxygen gas = 25.7 g
moles of oxygengas = 

According to reaction given above, 5 moles of oxygen gas reacts with 4 moles of ammonia gas.
Then 0.8031 moles of oxygen gas will react with :
of ammonia gas
0.6425 moles of
is required to react with 25.7 grams of
.
20000 nanograms sorry i cant answer the second question
Answer:
Fe will displace On but no the reaction is not vigorous.