The formation of NH3 via synthesis means that it must've been produced from simpler reactants — how about elemental hydrogen and nitrogen?
H + N → NH3
This isn't totally right, though — hydrogen and nitrogen are diatomic gases in nature, meaning they pair up like inseparable twins to stay stable:
H2 + N2 → NH3
Next, we need to balance this reaction to 1) obey law of conservation and 2) get correct molar ratios:
Balanced reaction: 3H2 + N2 → 2NH3
What volume of hydrogen will completely react with 22.4 liters of nitrogen?
22.4 L of any gas at standard temperature and pressure is the amount of space that 1 mole of gas takes up.
If we have 1 mol of N2, we need 3 mol of H2 based on the coefficients in our balanced reaction.
3 moles of H2 would take up 3(22.4L) of space = 67.2 L.
Here's the dimensional analysis set-up:
22.4 L N2 * 1 mol N2 / 22.4 L N2 * 3 mol H2 / 1 mol N2 * 22.4 L H2 / 1 mol H2 = 67.2 L H2
What volume of ammonia will be formed?
Using the same principles from the solution above, we can set up the dimensional analysis:
22.4 L N2 * 1 mol N2 / 22.4 L N2 * 2 mol NH3 / 1 mol N2 * 22.4 L H2 / 1 mol NH3 = 44.8 L NH3
