A. The complete balanced chemical reaction is:
PbS + 1.5 O2
---> PbO + SO2
B. First let us convert mass of PbS into number of moles.
The molar mass of PbS is 239.3 g/mol, hence:
moles PbS = 29.9 g/ (239.3 g/mol) = 0.125 mol
From the reaction, we need 1.5 moles of O2 for every 1
mole of PbS, therefore:
moles O2 = 0.125 mol * 1.5 = 0.1875 mol
The molar mass of O2 is 32 g/mol, hence the mass is:
mass O2 = 0.1875 mol * 32 g/mol = 6 grams O2
C. Converting mass to number of moles:
moles PbS = 65.0 g/ (239.3 g/mol) = 0.2716 mol
From the reaction, we can produce 1 mole of SO2 for every
1 mole of PbS, therefore:
moles SO2 = 0.2716 mol
The molar mass of O2 is 64 g/mol, hence the mass is:
mass SO2 = 0.2716 mol * 64 g/mol = 17.38 grams SO2
D. First let us convert mass of PbO into number of moles.
The molar mass of PbO is 223.2 g/mol, hence:
moles PbO = 128 g/ (223.2 g/mol) = 0.573 mol
From the reaction, we need 1 mole of PbS for every 1 mole
of PbO, therefore:
moles PbS = 0.573 mol
The molar mass of PbS is 239.3 g/mol, hence the mass is:
mass PbS = 0.573 mol * 239.3 g/mol = 137.23 grams PbS
