首先先看戊烷的同分异构，有正戊烷，异戊烷，和新戊烷，正戊烷有3种等效氢，异戊烷有4种等效氢，新戊烷有1种等效氢，3+4+1=8答案是8种
CH3CH2CH2CH2CH2OH CH3CH(CH3)CH2CH2OH CH3C(CH3)2CH2OH CH3CH(CH3)CH(CH3)OH CH3CH2C(CH3)2OH(CH3CH2)2CH2OH
