in water crystn. from components soln. on slow solvent evapn. at room temp.;

water in water boiling with small water pptn. with CaCO3, filtration from K2SO4; evapn.;

in water no reaction of an alkaline soln. of Na2S2O4 with KNO2 on standing on air;;

in water reaction of an aq. soln. of Na2S2O4 with KNO2 on standing on air; at first formation of NaHSO3; then reaction of NaHSO3 forming KNH2SO3, NaOH and NaHSO4;;

in water byproducts: N2O3; reaction of an acidic aq. soln. of Na2S2O4 with KNO2 on standing on air; at first formation of NaHSO3; then reaction of NaHSO3 forming KNH2SO3, NaOH and NaHSO4; reduction of N2O3 forming N2O;;