For the complete combustion of 1 mole of ethanol $\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right),$ the required number of moles of oxygen is_________
For the complete combustion of 1 mole of ethanol $\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right),$ the required number of moles of oxygen is_________