(1)113~450℃
(2)还原性;2H 2Se+O 2=2H 2O+2Se
(3)Al 2Te 3+6H 2O=2Al(OH) 3↓+3H 2Te
(4)H 2S(g)=H 2(g)+S(s);△H=+112.2kJ/mol
(5)氧气;硒