For the reaction
? C6H6 + ? O2 ↽⇀? CO2 + ? H2O
a maximum of ? moles of CO2 could be
formed from 6.38 mol of C6H6 and 6.03 mol
of O2.
Answer in units of mol
To determine the maximum number of moles of CO2 that can be formed, we need to first balance the chemical equation.
The balanced equation for the combustion of benzene (C6H6) can be written as follows:
C6H6 + 15/2 O2 → 6 CO2 + 3 H2O
To find the maximum number of moles of CO2 that can be formed, we need to compare the stoichiometric coefficients of C6H6 and CO2. The coefficient of C6H6 is 1, and the coefficient of CO2 is 6. This means that for every 1 mol of C6H6 used, 6 mol of CO2 is formed.
Given that there are 6.38 mol of C6H6, the maximum number of moles of CO2 that can be formed is:
6.38 mol C6H6 × 6 mol CO2 / 1 mol C6H6 = 38.28 mol CO2
Therefore, a maximum of 38.28 moles of CO2 could be formed from 6.38 mol of C6H6 and 6.03 mol of O2.
2C6H6 + 15O2 ==> 12CO2 + 6H2O
6.38 mol C6H6 x (12 mols CO2/2 mols C6H6) = 38.3 mols CO2 formed if we started with 6.38 mol C6H6 and had all of the O2 we needed.
6.03 mol O2 x (12 mols CO2/15 mol O2) = 4.82 mols CO2 formed if we started with 6.03 mol O2 and had all of the C6H6 we needed.
In limiting reagent problems the correct answer is ALWAYS the smaller value; therefore, the limiting reagent is O2 and we have some C6H6 remain unreacted. We will have a maximum of 4.82 mols CO2 formed.