Question

Beilstein test is used for the detection of which element in the organic compound?
A. $N$
B. $Cl$
C. $Na$
D. $P$

Answer 1

Hint: The Beilstein test is conducted to check the presence of a halogen (chlorine, bromine, or iodine) in an organic compound. A piece of copper wire or gauze is pre-heated strongly in the oxidizing flame of a Bunsen burner (until the flame is no longer green) and the test substance placed on the wire or gauze, which is re-heated. A green flame indicates the presence of a halogen.

Complete step by step answer:

The Beilstein test is a simple qualitative chemical test that is used to detect the presence of halogen in the organic halides. It was developed by Friedrich Konrad Beilstein. A copper wire is cleaned to get rid of the impurities and is heated over a Bunsen burner flame in order to form a coating of copper(II) oxide. It is then dipped in the sample to be tested and once again is heated over the flame. A positive test is indicated by a green flame caused by the formation of a copper halide. The test does not detect fluorine/fluorides.
This test is no longer frequently used these days. One reason why it is not widely used is that using this method, it is possible to generate the highly toxic chloro-dioxins if the test material is a polychloroprene which can be used as a hazardous bio-weapon causing mass destruction of lives.
Thus, the correct option is B. $Cl$ .

Note:
An alternative wet test for halide is the sodium fusion test. This test converts an organic material into its inorganic salts which include the sodium halide as well. Addition of silver nitrate solution causes any halides to precipitate into their respective silver halides.