In order to find limiting and excess reactants, we need to first, set up the equation, and it must be properly balanced:
C6H12O6 + 6 O2 -> 6 H2O + 6 CO2
1 gram of C6H12O6
1 gram of O2
From the balanced equation, we see that the molar ratio between C6H12O6 and O2 is 1:6, this means that 1 mol of C6H12O6 will react with 6 times the number of moles of O2
Now let's find the number of moles of C6H12O6, the molar mass is 180.16g/mol
180.16 g = 1 mol
1 g = x moles
x = 0.005 moles of C6H12O6, now we will need this number of moles times 6 in order to proceed with the reaction
1 C6H12O6 = 6 O2
0.005 C6H12O6 = x O2
x = 0.03 moles of O2
And this amount of moles with the molar mass of O2, which is 32g/mol
32 g = 1 mol
x grams = 0.03 moles
x = 0.96 grams of O2 in 0.03 moles
Since we have more oxygen than what we actually need, Oxygen is in excess and C6H12O6 is the limiting reactant
