HgO->O2->ZnO->H2O->Ba(OH)2

Question

HgO->O2->ZnO->H2O->Ba(OH)2

Answer 1

2HgO = 2Hg + O2
O2 + 2Zn = 2ZnO
H2S + ZnO = ZnS + H2O
2H2O + Ba = Ba(OH)2 + H2↑