In which of the following is intramolecular $H$-bonding absent?

Which among the following attractions is the strongest?

In ice,the length of $H$-bonds:

What are the two main requirements for the formation of a hydrogen bond?

Use the information and data given below to answer the questions $(a)$ to $(c)$. Stronger intermolecular forces result in higher boiling point.
Strength of London forces increases with the number of electrons in the molecule.
Boiling points of $HF, HCl, HBr$ and $HI$ are $293 \ K, 189 \ K, 200 \ K$ and $238 \ K$ respectively.
$(a)$ Which type of intermolecular forces are present in the molecules $HF, HCl, HBr$ and $HI$?
$(b)$ Looking at the trend of boiling points of $HCl, HBr$ and $HI$,explain out of dipole-dipole interaction and London interaction,which one is predominant here.
$(c)$ Why is the boiling point of hydrogen fluoride highest while that of hydrogen chloride lowest?

Why does $NH_{3}$ form hydrogen bond but $PH_{3}$ does not?