GALLIUM - Ga
Properties of Gallium:
Silver-white with a bluish shade, fusible, very soft, plastic metal. In solid and liquid states is formed by molecules of Ga2, gas - monatomic. It is passivated in cold water (is formed steady oxidic film). Strong reducer. Reacts with hot water, strong acids, alkalis, hydrate of ammonia, nonmetals.
| Molar mass | g/mol | 69.723 |
| Density | g/cm3 | 5.904 |
| Melting point | °C | 29.78 |
| Boiling point | °C | 2403 |
Methods for the preparation of Gallium:
Ga2O3 + 3H2 = 2Ga + 3H2O (700°C).
2GaCl3(melt) → Electrolysis → 2Ga↓(on cathode) + 3Cl2↑(on anode).
Сhemical reactions with Gallium:
2Ga + 6H2O(hot) = 2Ga(OH)3↓ + 3H2↑.
2Ga + 4H2O(steam) = 2GaO(OH) + 3H2 (350°C).
2Ga + 6HCl(diluted) = 2GaCl3 + 3H2↑.
Ga + 6HNO3(conc.) = Ga(NO3)3 + 3NO2↑ + 3H2O.
2Ga + 2NaOH(conc., hot) + 6H2O = 2Na[Ga(OH)4] + 3H2↑.
2Ga + 2(NH3·H2O)(conc., hot) + 6H2O = 2NH4[Ga(OH)4] + 3H2↑.
2Ga + 2Na2CO3(conc.) + 8H2O = 2Na[Ga(OH)4] + 3H2↑ + 2NaHCO3.
2Ga + O2 = 2GaO (burning on air).
2Ga + 3Cl2 = 2GaCl3 (80-200°C).
2Ga + 3S = Ga2S3 (800°C).
2Ga + 3H2S = Ga2S3 + 3H2 (250-350°C).
2Ga + 2NH3 = 2GaN + 3H2 (1050-1200°C).
