2KBr+Cl2-->2KCl+Br2↑
Br2+H2-->2HBr (t)
HBr+NaOH-->NaBr+H2O
NaBr+AgNO3-->AgBr↓+NaNO3
2Na + 2H2O = 2NaOH + H2
Na + 2HCl = NaCl2 + H2
2Na+ CO2 = Na2CO3
2Na + 2HBr = 2NaBr + H2
3Na + Al3PO4 = Na3PO4 + 3Al
Al + 2H3PO4 = AlPO4 + 3H2
2Al + 6HCl = 2AlCl3 + 3H2
2Al+ 3FeSO4 = Al2(SO4)3 + 3Fe
2Al + 3Zn(OH)2 = 2Al(OH)3 + 3Zn
2Al+ 3H2SO4 = Al2(SO4)3 + 3H2
1) HNO3 - H(+1), N(+5), O(-2)
NO2 - N(+4), O(-2)
NO - N(+2), O(-2)
N2O - N(+1), O(-2)
HN3 - H(+1), N(-3)
2) 2SO2 + O2 = 2SO3
S(+4) ==> S(+6), т. е. степень окисления серы уменьшается на 2.