(a) Draw the structures of the following molecules:
(i) H3PO2 (ii) ClF3
(b) Explain the following observations:
(i) Nitrogen is much less reactive than phosphorus.
(ii) Despite having greater polarity, hydrogen fluoride boils at a lower temperature than water.
(iii) Sulphur has a greater tendency for catenation than oxygen in the same group.
(i) H3PO2 (ii) ClF3
(b) Explain the following observations:
(i) Nitrogen is much less reactive than phosphorus.
(ii) Despite having greater polarity, hydrogen fluoride boils at a lower temperature than water.
(iii) Sulphur has a greater tendency for catenation than oxygen in the same group.
b)
i) Nitrogen molecule exist as N2 gas in which two nitrogen atoms are triply bonded so the presence of triple
bond makes the nitrogen bond strong and less reactive whereas phosphorus
exist as P4 molecule, where each phosphorus molecule is singly bonded hence it is weak and more reactive.
ii) Even though HF is polar and having hydrogen bonding it is shows
less boiling point because 1HF molecule form 1 hydrogen bond which can broken
down easily and can be boiled at low temperature where as in H2O one
molecule of H2O forms 2 hydrogen bonds so much heat is required to break
them.
iii) Oxygen is small in size and lone pair of oxygen atom repel bond pair of oxygen atom but is sulphur the lone pair of electron repel the bond pair of electron to smaller extent . Sulphur naturally exist as S8 molecule , on heating sulphur this bonds breaks and long chains formed. Hence sulphur has greater tendency for catenation than oxygen.
b)
i) Nitrogen molecule exist as N2 gas in which two nitrogen atoms are triply bonded so the presence of triple bond makes the nitrogen bond strong and less reactive whereas phosphorus exist as P4 molecule, where each phosphorus molecule is singly bonded hence it is weak and more reactive.
ii) Even though HF is polar and having hydrogen bonding it is shows less boiling point because 1HF molecule form 1 hydrogen bond which can broken down easily and can be boiled at low temperature where as in H2O one molecule of H2O forms 2 hydrogen bonds so much heat is required to break them.
iii) Oxygen is small in size and lone pair of oxygen atom repel bond pair of oxygen atom but is sulphur the lone pair of electron repel the bond pair of electron to smaller extent . Sulphur naturally exist as S8 molecule , on heating sulphur this bonds breaks and long chains formed. Hence sulphur has greater tendency for catenation than oxygen.
