Answer:
The empirical formula is MgS
The number of moles Mg is 0.25 moles
There will react 0.25 moles
Option A is correct
Explanation:
Step 1: data given
The molecular weight of Mg = 24.305 g/mol
The molecular weight of S is 32.065 g/mol
mass of crucible and cover = 27.631 grams
mass of crucible, cover and Mg = 33.709 grams
mass of crucible, cover, and the compound formed 41.725 grams
Step 2: Calculate mass of Mg
Mass of Mg = mass of crucible, cover and Mg - mass of crucible and cover
Mass of Mg = 33.709 grams - 27.631 grams
Mass of Mg = 6.078 grams
Step 3: Calculate moles Mg
Moles Mg = mass Mg / atomic mass Mg
Moles Mg = 6.078 grams 24.305 g/mol
Moles Mg = 0.250 moles
Step 4: Calculate mass compound
Mass compound = mass of crucible, cover, and the compound formed - mass of crucible and cover
Mass compound = 41.725 grams - 27.631 grams
Mass compound = 14.094 grams
Step 5: Calculate mass sulfur
Mass sulfur = 14.094 grams - 6.078 grams
Mass sulfur = 8.016 grams
Step 6: Calculate moles Sulfur
Moles sulfur = 8.016 grams / 32.065 g/mol
Moles sulfur = 0.250 moles
Step 7: Calculate the mol ratio
We diviide by the smallest amount of moles
Mg: 0.250 moles / 0.250 moles = 1
S: 0.250 moles / 0.250 moles = 1
The empirical formula is MgS
The number of moles Mg is 0.25 moles
There will react 0.25 moles
Option A is correct
