Fe+CuSO4=FESO4+CU
Na2CO3+2HCL=2NACL+H2O+CO2(气体箭头)
CuO+H2=(加热)=Cu+H2O
2Na+Cl2=点燃=2NaCl2
Zn+2Hcl=ZnCl2+H2(气体箭头)