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Tieria 發問於 科學及數學化學 · 1 十年前

關於Detection of substances的化學問題

1. A student collected samples of two minerals – X and Y. Both minerals are colourless and crystalline, though Y is obviously mixed with small amounts of a reddish brown solid. X is insoluble in water while Y is almost completely soluble. The following table shows the results of tests conducted on X and Y.





Flame test

X gave a dull red flame colour.

Y gave a yellow flame colour.


X was added to dilute hydrochloric acid

X dissolved in dilute hydrochloric acid with the evolution of a gas that turned limewater milky.


Dilute nitric acid was added to a solution of Y, followed by silver nitrate solution

A white precipitate formed.

a) The reddish brown solid mixed with Y is insoluble in water. Suggest how you would show that it contains iron(III) ion.

2 個解答

  • 1 十年前

    Reacting the solid with sodium hydroxide solution. Fe3+ gives reddish brown precipitate.

    Fe3+ (aq) + OH- (aq) -> Fe(OH)3 (s) <- reddish brown!!

    Hope my explanation help.

    資料來源: myself.
  • 1 十年前

    Test the reddish brown solid with sodium hydroxide solution. If reddish brown percipitaten is form, it contain iron(III) ion