EXPLANATION AND ANSWER CHEM

1. Well, CH3CH2NH2 actually can form hydrogen bonds, but N-H bonds are not hydrogen bonds. Recall back the definition of formation of hydrogen bond: the bond between the lone pair(s) of electrons of more electronegative atom (F, O, N) and the hydrogen atom. Therefore, N-H bonds only are said to be covalent bonds.

Refer back to the question, the molecules (alcohol, amine and alkane) given in the questions have the similar molecular size, so comparison is possible. Since alcohol can form more extensive hydrogen bonds than amine, boiling point of alcohol should be higher than amine. But alkane cannot form any hydrogen bond, the weak van der Waals' forces held between the molecules explains the lowest boiling point among the molecules.
Answer is D.

2. H2O has two lone pairs of electrons in O atom, so each H2O molecule can form two hydrogen bonds with other H2O molecules, while HF has only one lone pair of electrons in F atom, so each HF molecule can form one hydrogen bond with other HF molecules. Hence:
Boiling point of HF < Boiling point of H2O.
Answer is A.

You have wrong concept in hydrogen bonding.

N-H and O-H bonds are covalent bonds, but NOT hydrogen bonds.