Molar Volume is required to solve this problem. As we know that "1 mole of any gas at standard temperature and pressure occupies 22.4 L of volume". SO using this concept, we can calculate the volume of ammonia formed by reacting 54.1 L of Hydrogen gas as follow,
Divide 50 miles an hour or mph by 0.621, should give you 80.51 kilometers an hour or km/hr, this being the speed limit on that street in km/hr. If you're going 120 km/hr on an 80.51 kilometers an hour road you are speeding, as you're above the speed limit.
