Amongst ${\mathrm{H}}_2\mathrm{O}, {\mathrm{H}}_2\mathrm{S}, {\mathrm{H}}_2\mathrm{Se} \mathrm{and} {\mathrm{H}}_2\mathrm{Te}$ the one with the highest boiling point is:

1. H₂O because of H-bonding.

2. H₂Te because of higher molecular weight.

3. H₂S because of H-bonding.

4. H₂Se because of lower molecular weight.

Which of the following molecules exhibits H-bonding?

The correct order of the boiling points of \(\mathrm{H}_2 \mathrm{O}, \mathrm{HF}, \text{ and} \ \mathrm{NH}_3\) is: 

1. HF > H₂O > NH₃

2. H₂O > HF > NH₃

3. NH₃ > HF > H₂O

4. NH₃ > H₂O > HF