why is butanol more soluble in water as compared to butanamine?
In general you can say alcohols are more soluble than amines.
This is because O is more electronegative than N and thus O of -OH group forms more stronger hydrogen bond with N of -NH2 group.
O of butanol (an alcohol) forms stronger hydrogen bond with water molecules than N of butanamine (an amine), and hence butanol is more soluble in water as compared to butanamine