Which of the following is not a tranquilizer ?

Options

A. Barbituric acid
B. Seconal
C. Luminal
D. Phenacetin

Answer

To determine which of the following options is not a tranquilizer, we need to analyze each option provided:

1. **Barbituric Acid**:
- Barbituric acid is a precursor to barbiturates, which are known to have sedative and hypnotic properties. They are used to induce sleep and have a calming effect on the brain. Therefore, barbituric acid can be classified as a tranquilizer.

2. **Zirconol**:
- Zirconol is a type of barbiturate that is used to calm patients, especially before surgical procedures. It acts as a sedative and is considered a tranquilizer.

3. **Luminol**:
- Luminol is another drug that acts on the brain to stop abnormal electrical signals and is used for short-term treatment of anxiety and sleep disturbances. It also has calming effects and is classified as a tranquilizer.

4. **Phenacetin**:
- Phenacetin is primarily an analgesic and antipyretic medication, which means it is used to relieve pain and reduce fever. It does not have the properties of a tranquilizer and does not act on the brain to induce calmness or relaxation.

Based on the analysis above, the option that is not a tranquilizer is **Phenacetin**.

### Final Answer:
**Phenacetin** is not a tranquilizer.

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