Question

How many grams of O2(g) are needed to completely burn 64.3 g of C3H8(g)?

Answer 1

C3H8 + 5O2 --> 3CO2 +4H2O
no.of moles of C3H8=64.3/(3*12+8) =1.461363636moles
no.of moles of O2=1.461363636*5 =7.306818moles
mass of O2= 7.306818*(16*2)=233.81g