STRONTIUM - Sr

Properties of Strontium:

Alkaline earth metal. Light yellow, malleable. In the air is covered with oxide-nitride film. Colors the flame of a gas burner in a bright red color. High reactivity. Reacts with oxygen, nitrogen, hydrogen, halogen with heating. Strong reducing agent, oxidised by water, diluted acids, ammonia.


Molar mass g/mol 87.62
Density g/cm3 2.63
Melting point °C 768
Boiling point °C 1390

Methods for preparation of Strontium:

4SrO+ 2Al = 3Sr + (SrAl2)O4 (1200°C).

3SrCl2 + 2Al = 3Sr + 2AlCl3 (600-700°C).

SrCl2(liquid)→ Electrolysis → Sr(on cathode) + Cl2↑(on anode).


Сhemical reactions with metal Strontium:

Sr + 2H2O = Sr(OH)2↓ + H2↑ (normail temp.),

2Sr + H2O(vapor) = SrO + SrH2 (200-300°C).

Sr + 2HCl(diluted) = SrCl2 + H2.

4Sr + 10HNO3(diluted) = 4Sr(NO3)2 +N2O↑ + 5H2O,

4Sr + 10HNO3(highly diluted) = 4Sr(NO3)2 + NH4NO3 + 3H2O.

Sr + H2 = SrH2 (200-500°C).

Sr + O2 = 2SrO (over 250°C, burning on air).

Sr + Cl2 = SrCl2 (200-400°C).

3Sr + N2 = Sr3N2 (450-500°C, burning on air).

Sr + 2C(graphite) = SrC2 (500°C).

6Sr + 2NH3(gas) = Sr3N2 + 3SrH2 (600-650°C).

Sr + 6NH3(liquid) = [Sr(MH3)6](blue) [-40°C, in the atm. of Ar],

Sr + 2NH3(liquid) = Sr(NH2)2↓ + H2 (catalyst Pt).


 

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