405 PHz
I might be wrong because that might be for 0.74 nm. We will see with out people answers
The third answer is the one you want. You have to have an adjustable density. All other things being equal, if the tanks you use for holding just water when filled with water will let the sub sink, because the sub is made of a dense metal like iron or steel.
If on the other hand you fill these tanks with air, the net density will be below one and the sub will rise.
Explanation:
Moles of N2 = 84/28 = 3.0mol
Moles of H2 = 29/2 = 14.5mol
Hence amount of ammonia produced = 6.0 * 17 = 102g.
