MCQ Detailed View

In physical chemistry, the viscosity of a fluid measures its resistance to flow. A fluid with high viscosity flows slowly, while a fluid with low viscosity flows easily. The reciprocal of the coefficient of viscosity is called fluidity, often denoted by the symbol φ (phi).

Mathematically:

Fluidity(ϕ)=1Viscosity(η)\text{Fluidity} (\phi) = \frac{1}{\text{Viscosity} (\eta)}Fluidity(ϕ)=Viscosity(η)1

Fluidity is a measure of how easily a liquid can flow. A fluid with high fluidity flows readily, whereas a fluid with low fluidity resists motion. For example, water has a higher fluidity than honey at the same temperature because honey is more viscous.

Other options are incorrect:

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  Density is the mass per unit volume of a substance.

  
  


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  Specific gravity is the ratio of the density of a substance to the density of a reference substance (usually water).

  
  


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  Absorbance relates to light absorption and is not connected to flow properties.

  
  

Fluidity is an important property in industrial and chemical processes, such as lubrication, chemical engineering, and fluid transport. It is directly affected by temperature; as temperature increases, viscosity usually decreases, and fluidity increases. Understanding the relationship between viscosity and fluidity helps in designing pumps, pipelines, and fluid handling systems.

In summary, the reciprocal of viscosity is called fluidity, and it is a fundamental concept in physical chemistry, helping explain the flow behavior of liquids under various conditions.