Determine if the following reactions are homogeneous or heterogeneous reactions.
1) 2NO(g)+Br2(g)↽−−⇀2NOBr(g)
2) Al2O3(s)+6HClO4(aq)↽−−⇀2Al(ClO4)3(aq)+3H2O(l)
3)H2SO4(aq)+Fe(OH)3(s)↽−−⇀Fe2(SO4)3(aq)+H2O(l)
4) SiH4(g)+2Cl2(g)↽−−⇀CiCl4(g)+2H2(g)
5) Zn(s)+Cu(NO3)2(aq)↽−−⇀Cu(s)+Zn(NO3)2(aq