Question

Which of the following pharmaceutical solvent has the highest dielectric constant at 25°C?

• A. Glycerin
• B. Ethanol
• C. Acetone
• D. Phenol

Answer 1

The Correct Option is A

To determine which pharmaceutical solvent has the highest dielectric constant at 25°C, we need to understand the concept of dielectric constant, which is a measure of a substance's ability to insulate charges from each other. A higher value indicates a better ability to reduce the electrostatic forces between charged particles.

Let's analyze the given options one by one:

1. Glycerin: Glycerin is known to have a very high dielectric constant. At 25°C, its dielectric constant is approximately 47 to 48. This high value is due to its strong hydrogen bonding and viscous nature, which help stabilize electrical charges.
2. Ethanol: Ethanol has a dielectric constant of about 24.3 at 25°C. While moderate, it is significantly lower than glycerin.
3. Acetone: Acetone has a dielectric constant of approximately 20.7 at 25°C, which is lower than that of both ethanol and glycerin.
4. Phenol: Phenol has a dielectric constant of about 9.0 at 25°C, which is the lowest among the given solvents.

After comparing the dielectric constants of the mentioned solvents, it is clear that glycerin has the highest dielectric constant at 25°C.

Therefore, the correct answer is: Glycerin.