What are the two factors affecting viscosity?
The two main factors that affect viscosity are temperature and silica content.
What happens to a liquid when its temperature is raised?
An increase in the temperature of a liquid causes an increase in the average speed of its molecules. As the temperature of a liquid increases, the molecules move faster thereby increasing the liquid’s kinetic energy. This property can be shown in experiments by heating liquids.
What measures a material’s resistance to flow?
Viscosity is a measure of a fluid material’s resistance to flow and results from the internal forces and friction between the material’s molecules. Materials with low viscosity have low resistance to flowing and therefore flow very easily.
What causes viscosity in gases?
In the case of a gas, viscosity results from jumping of molecules from one layer of a gas to another layer. This means that the viscosity of a gas is caused by the transfer of momentum from one gas molecule to another. Thus, increasing the temperature of a gas will increase its momentum and thus the viscosity.
Does liquid have viscosity?
The viscosity decreases with an increase in temperature. Most liquids suffer the exponential relationship (Seeton, 2006) between temperature and viscosity rather than linear form (Fig. 6.1). The more viscous the fluid, the more sensitive it is to the temperature change.
What is the viscosity of gases?
The viscosity of a gas can be thought of as a measure of its resistance to flow and is measured in the CGS unit Poise = dyne sec/cm2. The viscosity of gases near room temperature are in the centiPoise range, so that is a commonly used unit. Gas viscosity is only weakly dependent on pressure near atmospheric pressure.
What is the most viscous gas?
Viscosity has the SI units Pascal seconds (Pa s) which is called the Poiseuille. More commonly used is the dyne sec/cm2 which is called Poise. One Pa s is 10 Poise….Viscosity of Liquids and Gases.
| Gases | Viscosity (Poise) |
|---|---|
| Nitrogen | 0.00018 |
| Oxygen | 0.00020 |
| Water vapor (steam) | 0.00013 |