You are provided with a sample and a strip of red litmus paper. How wo...
**Answer:**
To confirm the nature of the sample, we can perform a simple test using red litmus paper. The red litmus paper is an indicator that changes color in the presence of an acid. It turns blue when it comes in contact with a base or remains red if the solution is acidic.
The correct option to confirm the nature of the sample is option 'A': Dip the litmus paper in a dilute solution of NaOH and then put 2 drops of the liquid sample on it.
**Explanation:**
Here is a detailed explanation of why option 'A' is the correct choice for confirming the nature of the sample:
1. **Dip the litmus paper in a dilute solution of NaOH**: This step is performed to ensure that the litmus paper is not already acidic. If the litmus paper is already acidic, it will turn red and give a false positive result. By dipping it in a dilute solution of NaOH (sodium hydroxide), we neutralize any acidity present on the litmus paper.
2. **Put 2 drops of the liquid sample on the litmus paper**: After neutralizing the litmus paper, we put 2 drops of the liquid sample on it. If the liquid sample is acidic, the litmus paper will remain red, indicating the acidic nature of the sample. This is because acids turn litmus paper red and do not react with it.
3. **Interpretation of results**: If the litmus paper turns blue, it indicates that the liquid sample is basic. If the litmus paper remains red, it indicates that the liquid sample is acidic. This confirms the nature of the sample.
By following this procedure, we can accurately determine whether the liquid sample is acidic or basic. It is important to note that using the litmus paper directly in the sample (option 'B') may not yield accurate results if the litmus paper itself is already acidic or basic. Similarly, using a solution of NaCl (option 'D') does not provide the necessary information to confirm the nature of the sample.
Hence, option 'A' is the correct choice to confirm the nature of the sample using red litmus paper.
You are provided with a sample and a strip of red litmus paper. How wo...
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