ammonia; water in ammonia reaction of a soln. of Na2S2O4 and CuSO4 in aq. NH3; primary formation of CuH; then formation of Cu2SO4, Na2SO3, (NH4)2SO3 and (NH4)2SO4;;
mercury(II) cyanide in not given byproducts: Hg(CNS)2, NaCNS, HgS; reaction of Na2S2O3 with Hg(CN)2 in alcalical soln.; further byproducts: NaCN, Na2SO4;;