Cum am putea gandi:
fiind izomeri => au aceeasi masa, deci putem lua 100g compus C4H9Cl
...............71g......92,5g
C4H10 + Cl2 -> C4H9Cl + HCl
............x=76,75g..100g
100g amestec ..........76,75g Cl2
50g amestec ............38,37g Cl2
n=38,37/92,5=0,415moli
90/100=npractici/0,415=> npractici=0,3735moli
pV=nRT => V=nRT/p=0,3735*0,082*400/4=3,0627l Cl2