LITHIUM - Li

An alkali metal. A silvery-white. The easiest of the metals, soft, low melting. Reactive, air-oxide-nitride coated film. Ignited at a moderate heat, stains flame of a gas burner in a dark-red color. A strong reducing agent, reacts with water, acids, non-metals, ammonia.


Molar mass g/mol 6.941
Density g/cm3 0.534
Melting point °C 180.5
Boiling point °C 1336.6

Obtaining Lithium:

2LiH = 2Li + H2 (450°C).

2LiH (liquid) → Electrolysis → 2Li(on cathode) + H2↑(on anode).

2Li2O + Si = 4Li + SiO2 (1000°C).

Li2O + Mg = 2Li + MgO (t> 800°C).

3Li2O + 2Al = 6Li + Al2O3 (t> 1000°C).

2LiCl(liquid) → Electrolysis 2Li(on cathode) + Cl2↑(on anode).

2LiCl(melt) (on Hg-cathode) → Electrolysis → 2Li(on cathode) + Cl2↑(on anode).

2Li3N = 6Li + N2 (300-500°C, vacuum).


Reactions with Lithium:

2Li + 2H2O = 2LiOH + H2↑.

2Li + 2HCl(conc.) = 2LiCl + H2↑.

2Li + 3H2SO4(conc.) = 2LiHSO4 + SO2↑ + 2H2O.

3Li + 4HNO3(dilute) = 3LiNO3 + NO↑ + 2H2O.

2Li + H2 = 2LiH (500-700°C).

2Li + E2 = 2LiE (normal temp., E = F, Cl, Br; t>200°C, E = I).

4Li + O2 = 2Li2O (t>200°C, impurity Li2O2)

2Li + S = Li2S (t>130° C)

6Li + N2(moist) = 2Li3N (normal temp.)

6Li + N2 = 2Li3N (200-250°C, pressure)

2Li + 2C = Li2C2 (t>200°C, vacuum)

4Li + Si = Li4Si (600-700°C, impurity Li2Si)

2Li + 2NH3 = 2LiNH2 + H2 (220°C)

2Li + NH3 = Li2NH + H2 (400°C)

Li + 4NH3 (liquid) = [Li(NH3)4]0 (blue) [-40°C]

[Li(NH3)4]0 + nNH3(liquid) ↔ [Li(NH3)4]+ + e- + nNH3.


 

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