#Viscosity chemistry download

Therefore we may write, η = N m -2 or Pasġ Poise = 1 g cm -1s -1 = 0.1 kg m -1 s -1 Solved Examples For You Therefore we may write: η = dynes cm -2 sec or the units of viscosity are dynes sec cm -2.

#Viscosity chemistry download

You can download Mechanical Properties of Fluids Cheat Sheet by clicking on the download button belowīrowse more Topics under Mechanical Properties Of Fluids Hence the coefficient of viscosity may be defined as the force of friction required to maintain a velocity difference of 1 cm/sec between two parallel layers, 1 cm apart and each having an area of 1 sq cm. If dx =1, A = 1 sq cm dv = 1 cm/sec, then f = η. Where η is a constant known as the coefficient of viscosity and dv/dx is called velocity gradient. The force of friction f between two layers each having area A sq cm, separated by a distance dx cm, and having a velocity difference of dv cm/sec, is given by: Viscosity is the force of friction which one part of the liquid offers to another part of the liquid. In other words, every layer offers some resistance or friction to the layer immediately below it.

As we move from the centre towards the walls, the velocity of the layers keeps on decreasing. It is a type of flow with a regular gradation of velocity in going from one layer to the next. As we move from the wall towards the centre of the tube, the velocity of the cylindrical layers keeps on increasing till it is maximum at the centre. The layers which are in contact with the walls of the tube are almost stationary. Imagine the liquid to be made up of a large number of thin cylindrical coaxial layers. All parts of the liquids do not move through the tube with the same velocity. Hence, they are less viscous or have low viscosity.Ĭonsider a liquid flowing through a narrow tube. This is because of the weak intermolecular forces. The liquids which flow rapidly have a low internal resistance. Therefore, these liquids are more viscous and have high viscosity. This is because of the strong intermolecular forces. The liquids which flow slowly, have high internal resistance. There is quite a lot to discuss on viscosity in depth but these are just shallow concepts to understanding the term.It is the internal resistance to flow possessed by a liquid. It increases moderately with increasing pressure and markedly with decreasing temperature. The viscosity of simple liquids (i.e, pure liquids consisting of small molecules and solutions where solute and solvent are small molecules) depends only on composition, temperature, and pressure. The proportionality constant η is termed viscosity,ĭescribed as the internal friction in the fluid as it corresponds to the resistance of the fluid to the relative motion of adjacent layers Where the applied stress σ results in flow with a velocity gradient ỳ viscous flow, occurs in accordance with Newton’s law, Viscosity implies that the liquid flows even under the smallest stress and does not return to its original shape or form once the stress is removed. More simply, it can be consideredĪs a relative property, with water as the reference material.

Surface past another under specified conditions when the space between Viscosity is defined in terms of the force required to move one plane The more viscous a liquid is, the greater is the applied force required to make it flow at a particular rate. Viscosity is an expression of the resistance to flow of a system under an applied stress. More or less similar…I will try to put brief concepts of viscosity in terms of pharmaceutics which is somewhat another branch of chemistry, where it is very much applicable in drug design.