Uses of lithium :
i) It is used in the manufacture of alloys such as Li (0.05%) - Pb alloy used for making toughened bearings, Li - Al alloy is used for aircraft construction, Li (14%) - Mg alloy is used for armour plate and aerospace components.
ii) It is used for producing thermonuclear energy required for propelling rockets and guided missiles.
iii) LiOH is used in removing CO2 from exhaled air in submarines and space vehicles.
iv) LiBr is used in medicine as sedative while LiCl is used in air conditioning plants to regulate humidity.
Uses of sodium :
i) Sodium is used to make Na/Pb alloy needed to make PbEt4 and PbMe4. These are antoknocking additives in petrol.
ii) Liquid sodium metal is used as a coolant in fast breeder nuclear reactors.
iii) It is used as a reducing agent in the extraction of B and Si.
iv) It plays an important role in Wuetz reaction (as a reagent).
v) It is useful in making sodium vapour lamp.
Uses of potassium :
i) Potassium has vital role in biological system.
ii) Potassium chloride is used as a fertilizer.
iii) KOH is used in the manufacture of soft soap.
iv) KOH is used as an excellent absorbent of carbon dioxide.
v) Potassium superoxide is used as a source of oxygen is submarine, space shuttles and in emergency breathing apparatus. The moisture of breath with superoxide to liberate oxygen and KOH. Potassium hydroxide thus formed removes CO2 as it is exhaled thereby allowing the breathing apparatus (oxygen mask) to be continuously operated.
4KO2 + 2H2 → 4KOH + 3O2
KOH + CO2 → KHCO3
Use of caesium :
i) It is used in devising photo electric cells.