What is Al2S7? Important knowledge about Al2S7.

1. Definition of Al₂S₇
   Al₂S₇, or aluminium sulfide(VII), is a chemical substance belonging to the group of metal sulfides, which can be formed from the reaction between aluminum and sulfur.
   1.1 Names
   1.1.1 Common name: Aluminium sulfide(VII)
   1.1.2 English name: Aluminium sulfide
   1.2 Atomic mass: 306.07 g/mol
   1.3 Atomic structure
   1.3.1 Molecular structure: The Al₂S₇ molecule consists of two aluminium atoms and seven sulfur atoms.
   1.4 Ion structure: Al₂S₇ forms Al₃+ and S₂- ions after ionization.

2. Properties of Al₂S₇

2.1 Physical properties of Al₂S₇
State: Solid in standard conditions
Color: Black
Smell: No distinctive smell
PH: Not applicable in the solid state
2.2 Chemical properties of Al₂S₇: Colorless solid, insoluble in water, reacts strongly with water to form hydrogen sulfide, a gas with a distinctive foul smell.

3. Common chemical equations of Al₂S₇
   Reaction with water: Al₂S₃ + 6H₂O -> 2Al(OH)₃ + 3H₂S
   Reaction with acid: Al₂S₃ + 6HCl -> 2AlCl₃ + 3H₂S
   Reaction with base: Al₂S₃ + 6NaOH -> 2Na₃AlO₃ + 3H₂S
4. Synthesis of Al₂S₇

4.1 Laboratory synthesis of Al₂S₇: By heating aluminum with sulfur.
2Al + 3S -> Al₂S₃
4.2 Industrial synthesis of Al₂S₇: Not synthesized on an industrial scale due to the toxic nature of hydrogen sulfide.