Page 1 - Microsoft Word - Module-2

SUBJECT-CHEMISTRY

S-BLOCK ELEMENTS

SUB TOPICS – GENERAL CHARACTERISTICS OF COMPOUNDS OF THE
ALKALI METALS, CAUSE OF ANOMALOUS PROPERTIES OF LITHIUM,

DIFFERENCE BETWEEN Li AND OTHER ALKALI METALS, SIMILARITIES
BETWEEN Li AND Mg, SOME IMPORTANT COMPOUNDS OF Na,

BIOLOGICAL IMPORTANCE OF Na AND K

KEY NOTES:

GENERAL CHARACTERISTICS OF COMPOUNDS OF THE

ALKALI METAL

Oxides and hydroxides:

 The stability of peroxide and superoxide increases

down the group. It is due to the stabilization of large

cations through lattice energy effects.

 The oxides are hydrolyzed by water to form

hydroxide.

M O + H O 2MOH
2
2
M O + 2H 0 2MOH + H 0
2 2
2
2
2
2MO + 2H O 2MOH + H O + O
2
2
2
2
 The superoxide is paramagnetic.
 Na O is widely used as an oxidizing agent in
2
2
inorganic chemistry.