Qualitative analysis of organic compounds is performed by Lassaigne's test by fusion with metallic sodium, by which the covalent compounds are converted into ionic compounds. Extra elementsline `N,S,P` andhalogensaredetected by their usual tests.
Q. Beilstein test is given by:

Options

A. RX(X=Cl,Br,I)`
B. Urea
C. Thiourea
D. All

Answer

To solve the question regarding the Beilstein test, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding the Beilstein Test**:
The Beilstein test is a qualitative analysis method used to detect the presence of halogens (such as chlorine, bromine, and iodine) in organic compounds.

**Hint**: Remember that the Beilstein test specifically targets organic halides.

2. **Procedure of the Beilstein Test**:
In this test, a copper wire is heated in a flame until it forms a coating of copper oxide. This wire is then dipped into the organic sample and heated again in the flame.

**Hint**: Focus on the role of the copper wire and the heating process in the test.

3. **Observation of Results**:
A positive Beilstein test is indicated by the appearance of a green or blue flame. This coloration is due to the formation of cupric halides from the reaction of copper with halogens present in the sample.

**Hint**: The color of the flame is crucial for identifying a positive result.

4. **Analyzing the Given Options**:
- The first option, RX (where R is any organic group and X is a halogen), will give a positive Beilstein test due to the presence of halides.
- The second option, urea, and the third option, thiourea, can also yield a positive result because they can form volatile cupric cyanides, which may produce a bluish-green flame.

**Hint**: Consider the chemical nature of each compound and their potential reactions with copper.

5. **Conclusion**:
Since all the options (RX, urea, and thiourea) can give a positive Beilstein test, the correct answer is that all of the options are correct.

**Hint**: When multiple options can yield a positive result, look for the option that states "all of the above."

### Final Answer:
The Beilstein test is given by all of the options provided (RX, urea, thiourea), so the answer is option D: all of the above.