Question

SO2+O2 SO3 how many moles of O2 needed to combust 100.0g of sulfur dioxide

Answer 1

2SO2 + O2 ------> 2SO3

1) M(SO2)= 32.0 + 2*16.0 = 64 g/mol

2) 100.0 g SO2 * 1 mol SO2/64 g SO2 = 1.5625 mol SO2

3) 2SO2 + O2 ------> 2SO3

2 mol 1 mol

1.5625 mol x mol

x= 1.5625/2=0.78125 ≈ 0.7813 mol O2

Answer: 0.7813 mol O2.