AgNO3 CuSO4 aqueous Fehling ethanolic K2SO4 dichromate GDPS diglyme 2HCl TISAB hydroxide molal AcO dithionate pyrocatechol NaHCO3 phenolphthalein NaSCN Finacle hypochlorite NaBr solvated xQundstar iodine methanolic IO3 Spermidine HPO42 5H2O permanganate