When solid magnesium nitride reacts with water the reaction produces solid magnesium hydroxide and ammonia gas. If 22.9 grams of magnesium nitride are added to 31.0 grams of water, how many liters of ammonia should be produced (assuming standard temperature and pressure)?
Recommendations:
Write the balanced equation for the reaction.
Find the limiting reagent.
Use the # of moles of the limiting reagent to determine the number of moles of product.
Remember that, at standard temperature and pressure, 1 mol of ANY gas occupies a volume of 22.4L.
Which of the recommendations do you not know how to do? Post the ones you know how to do and explain in detail the problem you have with the others.
First, let's write the balanced equation for the reaction between solid magnesium nitride (Mg3N2) and water (H2O):
Mg3N2 + 6H2O -> 3Mg(OH)2 + 2NH3
From the balanced equation, we can see that the stoichiometric ratio between magnesium nitride and ammonia is 1:2. This means that 1 mole of magnesium nitride yields 2 moles of ammonia.
To find the limiting reagent, we need to compare the number of moles of magnesium nitride and water present. To do this, calculate the number of moles of each substance.
Number of moles of magnesium nitride = mass (g) / molar mass (g/mol)
Number of moles of water = mass (g) / molar mass (g/mol)
The molar mass of magnesium nitride is calculated by adding the atomic masses of magnesium (Mg) and nitrogen (N) in the compound:
Molar mass of Mg3N2 = (3 * atomic mass of Mg) + (2 * atomic mass of N)
The molar mass of water can be directly found by adding the atomic masses of hydrogen (H) and oxygen (O):
Molar mass of H2O = (2 * atomic mass of H) + atomic mass of O
Now, calculate the number of moles of magnesium nitride and water:
Moles of magnesium nitride = 22.9 g / molar mass of Mg3N2
Moles of water = 31.0 g / molar mass of H2O
Once you have the number of moles of the limiting reagent, you can determine the number of moles of ammonia produced. Since the stoichiometric ratio between magnesium nitride and ammonia is 1:2, the number of moles of ammonia will be twice the number of moles of the limiting reagent.
Number of moles of ammonia = 2 * moles of magnesium nitride (limiting reagent)
Finally, using Avogadro's law, we know that one mole of any gas at standard temperature and pressure (STP) occupies a volume of 22.4 liters. Therefore, the number of liters of ammonia produced will be equal to the number of moles of ammonia.
So, the number of liters of ammonia produced would be equal to the number of moles of ammonia.