In COD test by e dichromate mtd, write an equation to show e rxn btwn chloride and dichromate in acidic medium

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In COD test by e dichromate mtd, write an equation to show e rxn btwn chloride and dichromate in acidic medium

2007-06-03 01:19:02 · 2 answers · asked by XuaN 1 in Science & Mathematics ➔ Chemistry

2 answers

(Cr2O7)2- + 6Cl- + 14H+ -----> 2Cr3+ + 3Cl2 + 7H2O

2007-06-03 02:27:57 · answer #1 · answered by Gervald F 7 · 0⤊ 0⤋

1. The gas which turns lime water milky is carbon-di-oxide(CO2) Its due to the formation of calcium carbonate (CaCO3) from lime water Ca(OH)2 and CO2 . but one thing if pass too much of CO2 then the precipitate dissolves and you get a clear solution because of the water soluble calcium-bi-carbonate(CaHCO3) 2. The gas which turns acidic dichromate paper green is sulfur-di-oxide(SO2) SO2 reduces Cr6+ of dichromate to green Cr3+.

2016-04-01 13:09:36 · answer #2 · answered by Anonymous · 0⤊ 0⤋