posted by jessie .
write a balanced reaction for 50.92 grams of carbon disulfide,including molar masses. then calculate the moles of carbon disulfide and oxygen. now find the mass of oxygen consumed in the reastion.
CS2 + 3O2 ==> CO2 + 2SO2
Your question isn't completely clear as to the reaction. I assume the above is it. Now you write in what you know and tell us what you don't understand.
1 mole of CS2 = 12.011 + 32.066x2 = 76.143 g/mol
(50.92 g) / (76.143 g/mol) = 0.66874 moles CS2
Based on the chemical equation DrBob gave you for the combustion of CS2,
(0.66874 mol CS2)(3 mol O2 / 1 mol CS2) = ___moles O2
To get the mass (grams) of O2 consumed in the reaction, multiply the moles of O2 by the molar mass of O2.