Weight of empty crucible and cover = 23.104 g
Weight of crucible, cover, MgO and Mg3N2 = 24.199 g
Weight of crucible, cover, MgOand addition of H2O and heat = 24.290
Calculate the number of moles of Mg3N2.
The change in mass was 0.0910g
If you mean the mass Mg3N2 = 0.0910 then mols = grams/molar mass
To calculate the number of moles of Mg3N2, we need to determine the change in weight caused by the addition of Mg3N2 in the crucible.
Given:
Weight of empty crucible and cover = 23.104 g
Weight of crucible, cover, MgO, and Mg3N2 = 24.199 g
Change in weight = (Weight of crucible, cover, MgO, and Mg3N2) - (Weight of empty crucible and cover)
= 24.199 g - 23.104 g
= 1.095 g
Now, we need to convert the change in weight to moles of Mg3N2 using its molar mass.
The molar mass of Mg3N2 = (2 × molar mass of Mg) + (2 × molar mass of N)
= (2 × 24.31 g/mol) + (2 × 14.01 g/mol)
= 48.62 g/mol + 28.02 g/mol
= 76.64 g/mol
Number of moles of Mg3N2 = (Change in weight in grams) / (Molar mass in grams/mol)
= 1.095 g / 76.64 g/mol
≈ 0.014 mol
Therefore, the number of moles of Mg3N2 in the crucible is approximately 0.014 mol.
To calculate the number of moles of Mg3N2, we need to follow these steps:
1. Find the mass of Mg3N2 in the crucible, cover, MgO, and Mg3N2 mixture by subtracting the weight of the empty crucible and cover from the weight of the crucible, cover, MgO, and Mg3N2 mixture:
Mass of Mg3N2 = Weight of crucible, cover, MgO and Mg3N2 - Weight of empty crucible and cover
= 24.199 g - 23.104 g
= 1.095 g
2. Calculate the number of moles of Mg3N2 using its molar mass. The molar mass of Mg3N2 can be determined by adding up the atomic masses of magnesium (Mg) and nitrogen (N):
Molar mass of Mg3N2 = (3 * atomic mass of Mg) + (2 * atomic mass of N)
= (3 * 24.31 g/mol) + (2 * 14.01 g/mol)
= 72.93 g/mol + 28.02 g/mol
= 100.95 g/mol
Number of moles of Mg3N2 = Mass of Mg3N2 / Molar mass of Mg3N2
= 1.095 g / 100.95 g/mol
Therefore, the number of moles of Mg3N2 in the given sample is approximately 0.01085 moles.