Viscosity is a material property which describes the resistance of a fluid to shearing flows. It corresponds roughly to the intuitive notion of a fluid’s ‘thickness’. For instance, honey has a much higher viscosity than water.

One of the most viscous liquids known is pitch, also known as bitumen, asphalt, or tar. Demonstrating its flow and measuring its viscosity is the subject of the longest continuously running scientific experiment, begun in 1927 at the University of Queensland in Australia.

To think of viscosity in everyday terms, the easier a fluid moves, the lower the viscosity. Using our earlier example, which fluid has a greater viscosity? Honey would move slower than water, so honey would have a greater viscosity.

Method

1. Place 50 ml of each honey sample into separate measuring cylinders.
2. Place each sample into a water bath at 37ºC and bring to temperature.
3. Place a marble or ball bearing on top of the honey and time how long it takes for the object to touch the bottom of the measuring cylinder.

Honey in part is more viscous (thick) than water due to strong inter-molecular forces. Fluids with low viscosity have a low resistance to shear forces, and therefore the molecules flow quickly and are easy to move through. A fluid that has no resistance to shear stress is known as an ideal fluid or inviscid fluid.

Out of all the liquids I tested (honey, water, milk, cooking oil, glycerin, hand sanitizer, and syrup), honey is the most viscous and milk is the least. Engineers, doctors, volcanologists, and scientists all use viscosity in practical life.

Explanation: Here Oil is the most viscous liquid. The liquid with the most intermolecular force is high viscous. viscosity is how smoothly a liquid flows and how hardly the liquid flows it is highly viscous.

Data from Gustafson. These viscosities are at 20°C except for the blood and blood plasma which are at body temperature, 37°C, and for steam which is at 100°C….Viscosity of Liquids and Gases.

(i) Glycerine has stronger intermolecular forces than water hence, it is more viscous than water.

Acetone has a viscosity 3x less than water but weighs 2.5 times more.

Glycerol is more viscous than ethane because of the expensive hydrogen bonding in glycerol. Alcohol also exhibit hydrogen bonding but glycerol contains three on per molecule and alcohol has only are OH group that can exhibit H−bonding.

This medication is used as a moisturizer to treat or prevent dry, rough, scaly, itchy skin and minor skin irritations (e.g., diaper rash, skin burns from radiation therapy). Emollients are substances that soften and moisturize the skin and decrease itching and flaking.