0.197g of magnesium is burned in air
2Mg + O2 ---> 2MgO
However, some of the magnesium reacts with nitrogen in the air to form Magnesium nitride instead : 3Mg + N2 --->Mg3N2
So you have a mixture of MgO and Mg3N2 weighing 0.315g.Determine what percentage of the Mg formed the nitride in the initial reaction.
Again, look at your MO2/M2S3 problem.
21.5%
45%
To find out the percentage of magnesium that formed the nitride in the initial reaction, we first need to determine the amount of magnesium that reacted to form magnesium oxide (MgO).
Let's assume that x grams of magnesium reacted to form MgO. Therefore, the amount of magnesium that reacted to form magnesium nitride (Mg3N2) would be (0.197g - x) grams.
Now, we can determine the amount of MgO and Mg3N2 formed using the given information.
According to the balanced equation, the molar ratio between Mg and MgO is 2:2. This means that for every 2 moles of Mg, we will get 2 moles of MgO. Similarly, the molar ratio between Mg and Mg3N2 is 3:1, so for every 3 moles of Mg, we will get 1 mole of Mg3N2.
Using the molar masses of MgO (40.31 g/mol) and Mg3N2 (100.93 g/mol), we can calculate the amount of MgO and Mg3N2 formed:
Amount of MgO formed = (mol ratio of MgO / mol ratio of Mg) * x * (molar mass of MgO)
Amount of Mg3N2 formed = (mol ratio of Mg3N2 / mol ratio of Mg) * (0.197g - x) * (molar mass of Mg3N2)
Since we have a mixture of MgO and Mg3N2 with a total mass of 0.315g, we can set up the following equation:
Amount of MgO formed + Amount of Mg3N2 formed = 0.315g
Substituting the calculated values, we get:
((2/2) * x * (40.31 g/mol)) + ((1/3) * (0.197g - x) * (100.93 g/mol)) = 0.315g
Now, we can solve this equation to find the value of x, which represents the amount of magnesium that reacted to form MgO.
Simplifying and solving the equation will give us the value of x. Once we have it, we can find the percentage using the following formula:
Percentage of magnesium forming the nitride = [((0.197g - x) / 0.197g)] * 100%
So, by calculating x and substituting its value in the above formula, we can find the percentage of magnesium that formed the nitride in the initial reaction.