-calculez volumul de oxigen,din ecuatia chimica, stiind M,C6H6=78g/mol si Vm= 22,4l/mol(volumul molar)
1mol.........7,5mol
C6H6 + 15/2O2----> 6CO2+3H2V.
78g............7,5x22,4 l
1g......................x= 2,154 l O2
V aer= 20/100xV,O2=........................CALCULEAZA !!!!!