2C2H6 +7O2 --> 4CO2 + 6H2O

Question

If 6 moles of O2 are used in the following reaction, how many grams of CO2 will be produced?

Answer 1

2C2H6 +7O2 --> 4CO2 + 6H2O
since this is already a balanced equation, we can now use their stoich coefficients for the ratios.
first, since we need grams of CO2, we find it's molecular mass. from the periodic table, the masses of C and O are
C = 12 and O = 16 , thus
1*12 + 2*16 = 44 g/mol
therefore,
6 mol O2 * (4 mol CO2 / 7 mol O2) * (44 g CO2 / 1 mol CO2) = 150.86 g CO2

hope this helps~ :)