In determing the simplest formula of lead sulfide, 2.46 grams of of lead are placed in a crucible with 2.00 grams of sulfur. when the reaction is complete, the product has a mass of 3.22 grams. What mass of sulfur should be used in the simplest formula calculation? Find the simplest formula of lead sulfide
mass Pb = 2.46g.
mass S = 3.22-2.46 = ?
Convert 2.46g to mols. mol = g/atomic mass
mols S = (3.22-2.46)/atomic mass S.
Now find the ratio of the elements to each other to determine the empirical formula.
3.22-2.46=.76.
Now mols Pb = grams/atomic massPb
mols S = grams/atomic mass S
Then find ratio of the elements to each other.
To determine the simplest formula of lead sulfide, we need to find the ratio between the number of lead atoms (Pb) and sulfur atoms (S) in the compound.
Step 1: Calculate the number of moles for each element.
- Moles of lead (Pb) = mass of lead (g) / molar mass of lead (g/mol)
- Moles of sulfur (S) = mass of sulfur (g) / molar mass of sulfur (g/mol)
The molar mass of lead (Pb) is 207.2 g/mol, and the molar mass of sulfur (S) is 32.06 g/mol.
Moles of lead (Pb) = 2.46 g / 207.2 g/mol = 0.0119 mol
Moles of sulfur (S) = 2.00 g / 32.06 g/mol = 0.0623 mol
Step 2: Find the ratio between the moles of lead and sulfur.
Divide both moles by the smaller value to get the simplest ratio.
Ratio (Pb : S) = Moles of lead (Pb) / Moles of sulfur (S)
Ratio (Pb : S) = 0.0119 mol / 0.0119 mol = 1 : 5.23 (approximately)
Step 3: Find the mass of sulfur required for the simplest formula calculation.
To do this, we multiply the ratio of sulfur to lead by the molar mass of sulfur.
Mass of sulfur = Ratio (Pb : S) * Molar mass of sulfur
Mass of sulfur = 5.23 * 32.06 g/mol = 167.82 g
Therefore, the mass of sulfur that should be used in the simplest formula calculation is 167.82 grams.
Step 4: Determine the simplest formula of lead sulfide.
The ratio of 1 : 5.23 tells us that for each lead atom, there are approximately 5.23 sulfur atoms. Since we cannot have a fraction of an atom, we round this ratio to the nearest whole number.
Rounded ratio (Pb : S) = 1 : 5
Thus, the simplest formula of lead sulfide is PbS.