1)Nh3=3h2+?+q 2) MgO+HCl-?+H2 3)Al+HCl-?+h2 4)Al+s-?
2NH3=3H2+N2+Q MgO+2HCl=MgCl2+H2O 2Al+6HCl=2AlCl3+3H2 2Al+3S=Al2S3