Three liters of nitrogen combine with 9 L of hydrogen to form 6 L of ammonia. If the molecules of nitrogen and hydrogen have two atoms each, how many atoms of hydrogen and nitrogen are there in one molecule of ammonia?

To determine how many atoms of hydrogen and nitrogen are there in one molecule of ammonia, we need to compare the number of moles of hydrogen, nitrogen, and ammonia.

First, let's calculate the number of moles of nitrogen and hydrogen using their given volumes and the fact that one mole of any gas occupies 22.4 liters at standard temperature and pressure (STP).

Number of moles of nitrogen:
3 L / 22.4 L/mol ≈ 0.134 moles

Number of moles of hydrogen:
9 L / 22.4 L/mol ≈ 0.402 moles

Now, since the reaction between nitrogen and hydrogen produces ammonia in a 1:3 ratio, the number of moles of ammonia will be three times the number of moles of nitrogen.

Number of moles of ammonia:
0.134 moles × 3 = 0.402 moles

Now, let's focus on the ratio of moles in the balanced chemical equation for the reaction of nitrogen and hydrogen to form ammonia:

N₂ + 3H₂ → 2NH₃

From the balanced equation, we can see that one molecule of nitrogen (N₂) reacts with three molecules of hydrogen (3H₂) to form two molecules of ammonia (2NH₃). Therefore, in one molecule of ammonia, there is only one nitrogen atom and three hydrogen atoms.

So, to answer the question, there is one nitrogen atom and three hydrogen atoms in one molecule of ammonia.