What makes viscosity

This is because the molecular chains get tangled up in each other like spaghetti—in order for the liquid to flow, the molecules must first unravel. Fuel oil, lubricating grease, and other long-chain alkane molecules are quite viscous for this reason.

The video below shows several different long chained oils, each progressively more viscous. The viscosity of a liquid always decreases as temperature increases. This can be also understood as friction between the molecules in the fluid. Just like in the case of friction between moving solids, viscosity will determine the energy required to make a fluid flow.

Viscosity can be measured using various methods from do-it-yourself methods to viscometers that are available in the market. Watch our webinar on the different types of viscosity! You can think in terms of different fluids taking different times to, for example, pour out of a cup. Water will pour out of a glass in a fraction of a second and will take the shape of the receiving container in just as short of a time. On the other hand, a high viscosity fluid like honey would take minutes to pour out and the interface between honey and air would take just as long to settle.

You might have notice that I have been talking about time when trying to establish which of those two fluids is more viscous. That's what we refer to as a measurement of kinematic viscosity or how fast does a fluid flow for a given force applied to it. Viscosity is the measure of resistance of a fluid to flow. A fluid that is highly viscous has a high resistance like having more friction and flows slower than a low-viscosity fluid.

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. Pressure and temperature are also considered when talking about the viscosity of a liquid.

He also served as a newspaper reporter in Australia. Beglan holds a Bachelor of Science in chemistry and a foundation degree in communications, both from the University of London. How to Convert From Centistoke to Centipoise. How to Read a Manometer. How to Calculate Density From Viscosity.

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