The number of people this planet can support is largely determined by the amount of ammonia-based fertilizer that can be produced. Without the ability to chemically manufacture ammonia, the world's population would be closer to 1/6 of its current size. Since the early twentieth century ammonia has been produced via the process shown below.
3 H2 + N2 -- 2 NH3
How many grams of ammonia are produced when 24.00 g of H2 react?