(a) Nitrogen and chlorine have almost same `EN'` s but `N` forms H-bonding
(b) `H_(2)O` is liquid whereas `H_(2)S` is gas
(c ) Compare the acidic strength of o-,m-and p-hydroxy benzoic acid
`(d)NH_(3)` exists as liguid whereas `HCI` as gas
(e) Among the compounds `CH_(3)COOH,NH_(3)HF` and `CH_(4)` in which the strongest H-bonding is persent (f) Among `HF,CH_(3) OH, N_(2)O_(4)` amd which would have intermolecular H-bonding
(g) Salt-like `KHF_(2)` is stable but `KHCI_(2)` is not known (h) `H_(3)PO_(4)` is a syrupy liquid
(i) `H_(2)SO_(4)` is colourless viscous oily liquid and has high boiling point
(j) Water forms four H-bonds as compared to two in `HF` EXplain
(k) Density of ice is less than that of water or ice floats over water .

Explanation

(a) Due to the large size of `CI` interacting with neighbouring molecules is not so strong
(b) In `H_(2)O` there are stron intermolecular forces due to extensive H-bonds No such bonding exists in `H_(2)S` since `EN` of `OgtEN` of `S`
(c ) Stregth of certain acids and bases can be explained on the basis of H-bonding The abnormally high ka or low `pK_(a)` value of o-hydroxybenzoic acid is due to the fact that the conjugate base is stabilised by h-boding Decreasing acidic strength order is ltbr. (d) The size of `N` atom is less than the size of `CI`atom therefore electron density in `N` is more than that of `CI` So `N` forms H-bonding leading to association of molecule Hence `NH_(3)` is liquid H-bonding is not possible with `CI`
(e) `HF` due to maximum `EN` of `F` Decreasing order of strength of H-bonding
`HF gt NH_(3) gt CH_(3) COOH` (exist as dimer) gt `CH_(4)`
(f ) `HF` and `CH_(3) OH`
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