n1 moli C6H5-CH3 + Cl2 = H3C-C6H4-Cl (para) + HCl
n2 moli C6H5-CH3 + Cl2 = H3C-C6H4-Cl (orto) + HCl
n3 moli C6H5-CH3 + Cl2 = H3C-C6H4-Cl (meta) + HCl
n4 moli C6H5-CH3 nereactionat
masa de reactie = 126,5n+126,5n2+126,5n3+92n4=126,5(n1+n2+n3)+92n4=m
126,5n1·100 = 50m n1/n2 = 5/4 n2 =4n1/5
126,5n2·100 = 40m n2/n3 = 8/1 n3 = n2/8
126,5n3·100 = 5m
92n4·100 = 5m
ptr. n1 = 1/126,5 moli ⇒ n2 = 0,8/126,5 moli n3 = 0,1/126,5 moli
126,5n3 = 92n4 n4 = 126,5n3/92 = 0,1/92 moli
m toluen= 92(n1+ n2 + n3 + n4) =92(1/126,5 + 0,8/126,5 + 0,1/126,5 + 0,1/92)
= 92·1,9/126,5 + 0,1 = 1,48 kg