Answer:
1) 3Fe + 2O(2, this is the subscript) - Fe(3)O(4)
2) 2Sr + O(2) - 2SrO
3) Sn + 2NaOH - Na(2)SnO(2) + H(2)
4) 2K + Br(2) -2KBr
5) 2C(8)H(18) + 25O(2) - 16CO(2) + 18H(2)O
