I put calcium carbonate into k2cr2o7 to make cacro4. caco3 don't dissolve. I put na2co3 into k2cr2o7 to make k2cro4. na2co3 dissolve and solution
become yellow. Why don't the caco3 dissolve like na2co3?walruslover69 - 2-8-2019 at 08:39
If you don't have an understanding of basic solubility rules, you definitely shouldn't be working with chromates/dichromatesTmNhRhMgBrSe - 2-8-2019 at 08:39
I put some calcium nitrate into slightly acidified k2cro4 to make cacro4. some precipitate formed but solution become very orange. Why?TmNhRhMgBrSe - 2-8-2019 at 08:44
I put some calcium nitrate into slightly acidified k2cro4 to make cacro4. some precipitate formed but solution become very orange. Why?
It depends on the amount of acid, but when acidity is increased, the dichromate converts partially to trichromate which has a deep red color.
I think this is the reaction
I added a few drops of acid into the chromate so it should have a few % dichromate before adding excess calcium nitrate. All chromate should
precipitate as cacro4. The solution should contain some remaining dichromate. Is that acidic enough to form trichromate?vmelkon - 3-8-2019 at 18:38
I put some calcium nitrate into slightly acidified k2cro4 to make cacro4. some precipitate formed but solution become very orange. Why?
I think I know why now. The calcium nitrate has some remaining nitric acid. I found out this by adding this
solution to some new calcium carbonate.MrHomeScientist - 21-8-2019 at 06:51
Good job sticking with it and performing your own testing! It's very rewarding to figure out problems like this.
