Question

Debye is a unit of:

• A. Dipole moment
• B. Field effect
• C. Dissociation constant
• D. Bond energy

Hint:

Dipole moment reflects the polarity of a molecule and is commonly expressed in Debye. Polar molecules like H\textsubscript{2}O have a higher dipole moment than nonpolar molecules like CO\textsubscript{2}.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Every physical quantity in chemistry is reported using units that match what it measures, such as energy in joules or concentration in moles per liter. The Debye is one such unit, and identifying what it measures means recalling which quantity is conventionally reported in Debye.

Step 2: Key Formula or Approach:
Dipole moment is defined as
\[ \mu = q \times d \]
where q is the magnitude of the separated charge and d is the distance between the charges. When this product is calculated in SI units, coulomb meters, the resulting numbers are extremely small, around \(10^{-30}\), which is inconvenient to write repeatedly.

Step 3: Detailed Explanation:
Chemists defined the Debye as a scaled unit for exactly this quantity, with
\[ 1\ \text{D} = 3.336 \times 10^{-30}\ \text{C}\cdot\text{m} \]
so that dipole moments could be written as small, easy to compare numbers like 1.85 D for water instead of a value with thirty zeros after the decimal point.
None of the other three quantities in the options use this unit. Field effect is a qualitative influence and is not assigned a standard numeric unit at all. Dissociation constant is expressed using concentration units such as moles per liter. Bond energy is reported in energy units such as kilojoules per mole.

Step 4: Final Answer:
The Debye is the unit used to express dipole moment.