Viscosity of a liquid implies the viscous force that tends to prevent the relative motion of a liquid layer compared to another layer in its contact.
The coefficient of viscosity ‘n’ is the numerical measure of viscosity, and it is defined as the frictional force, F per unit area per unit velocity gradient i.e.,
A is the surface area and
dv/dx is the velocity gradient.
On addition of a solute having larger molecular size and increased intermolecular forces, the coefficient of viscosity of water increases. Thus, addition of a solute increases the viscosity of water. With increase in its concentration, the viscosity of the solution is increased further.
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