Question

Ammonium perchlorate NH4ClO4 is a powerful solid rocket fuel, used in the Space Shuttle boosters. It decomposes into nitrogen N2 gas, chlorine Cl2 gas, oxygen O2 gas and water vapor, releasing a great deal of energy. Calculate the moles of nitrogen produced by the reaction of 0.090mol of ammonium perchlorate. Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits.

Answer 1

First step is to set up the equation and also properly balance it:

2 NH4ClO4 -> N2 + Cl2 + 4 H2O + 2 O2

Now the reaction is properly balanced, so we can focus on what the question is giving and asking. The question gave us 0.090 moles of NH4ClO4 and wants to know how many moles can we make of Nitrogen gas from this, so forget all the other compounds and only look at these 2 molecules. So what is the molar ratio between these 2? 2:1 of molar ratio, because if you look at the equation you will see that with 2 moles of ammonium perchlorate I will have 1 mol of Nitrogen gas, now we can do the following calculation:

2 NH4ClO4 = 1 N2

0.090 NH4ClO4 = x N2

x = 0.045 moles of N2 will be produced