Un alcan cu M=72g/mol prezinta dupa clorurare un singur izomer monoclorurat si 2 izomeri diclorurati.Alcanul respectiv e?
1. 2-metil butan
2. 2,2 dimetil-propan
3. n-pentan
4. neopentan
Pai, alcanii au formula CnH2n+2 =>
12n+2n+2=72 => 14n+2=72 => 14n=70 => n=5 => alcanul are formula C5H12
....deci alcanul nostru iubit este:........neopentanul...deci raspunsul 4 ( D ) e corect
 
       C                                   C                                                     C - Cl
        l                                     l                                                     l
 C - C - C                       C - C - C - Cl                                C - C - C       
        l                                     l                                                    l
       C - Cl                             C - Cl                                           C - Cl