How many moles of sulfur are needed to produce 15.0 mol of sulfur dioxide?

S + O2 =  SO21 mole S ------------- 1 mole SO2( moles S ) --------- 15.0 moles SO2moles S = 15.0 x 1 / 1moles S = 15.0 / 1= 15.0 moles S