Na+Br2=/Zn+HCI=/Na+H2O=/Zn+S=/Mg+HgCI2=/Ca+HNO3=Ca(NO3)+N2+N2O
2Na+Br2=2NaBr
Zn+2HCl=ZnCl2+H2
2Na+2H2O=2NaOH+H2
Zn+S=ZnS
Mg+HgCl2=MgCl2+Hg
4Ca+10HNO3=4Ca(NO3)2+N2O+5H2O