Why does viscosity change with temperature?

In summary, the viscosity of a fluid changes with temperature due to the increase in kinetic energy of the particles. In gases, this leads to an increase in viscosity, while in liquids, it results in a decrease due to the weakening of intermolecular forces. This explanation may not fully address the question of the exponential decay of viscosity with temperature, but it provides a general understanding of the relationship between temperature and viscosity.
  • #1
Macca604
4
0
Does anybody know why viscosity changes with temperature?

I'm expected to do a short explanation or suggestion for my homework of why this happens but to be honest I'm not sure. :confused:

The only reason I can think of is higher temperature means more energy therefore less internal resistance to movement but that is quite a poor explanation.

Could anybody explain to me why viscosity decreases with temperature increase?
 
Physics news on Phys.org
  • #2
What have you found so far with your google search?
 
  • #3
berkeman said:
What have you found so far with your google search?

"When a fluid is heated, the particles within the fluid gain kinetic energy, and will be more able to overcome the intermolecular attraction forces within the fluid."

I think this will be enough actually, but I'm not sure why the decrease is an exponential decay.
 
  • #4
You have answered only half of the real question. Can you explain why the viscosity of a gas increases with temperature while viscosity of a liquid decreases with temperature? They are both fluids.
 
  • #5
I meant just liquids.
 
  • #6
viscosity is dependant on both momentum interchange and cohesive forces. In gases, momentum interchange is dorminant..as the temp. of the gas is raised, particles gain kinetic energy and therefore on collision, there's a greater transfer of momentum which results in the inrease in viscosity. In liquids, cohesive forces dorminate...when temperatures are raised, particles gain energy enouigh to overcome the intermolecular forces of attraction thus decreasing the cohesive forces. Decrease in these cohesive forces reduces the viscosity in the liquid.
 
  • #7
does that help ?
 
  • #8
tim ek said:
does that help ?

It probably doesn't help Macca604, since this thread is 4 years old. But it may help others who search for this subject.

Welcome to the PF.
 
  • #9
...4 what ? damn!
 
  • #10
tim ek said:
...4 what ? damn!

For which? The necropost miss, or that fact that it might help others in the future?
 
  • #11
..the necropost miss.
 

Related to Why does viscosity change with temperature?

1. Why does viscosity decrease with an increase in temperature?

Viscosity is a measure of a fluid's resistance to flow. When the temperature of a fluid increases, the particles within the fluid gain more kinetic energy and move faster, resulting in weaker intermolecular forces and less resistance to flow. This leads to a decrease in viscosity.

2. How does temperature affect the viscosity of liquids and gases differently?

In general, liquids have a higher viscosity than gases at the same temperature. As the temperature of a liquid increases, the average distance between particles increases, weakening the intermolecular forces and decreasing viscosity. In gases, an increase in temperature causes the particles to move faster, resulting in more collisions and higher viscosity.

3. What is the relationship between temperature and viscosity?

The relationship between temperature and viscosity is an inverse one. As temperature increases, viscosity decreases. Similarly, as temperature decreases, viscosity increases. This relationship is known as the Arrhenius equation and is used to calculate the viscosity of a fluid at different temperatures.

4. Can a change in temperature significantly alter the viscosity of a fluid?

Yes, a change in temperature can have a significant impact on the viscosity of a fluid. For example, the viscosity of honey at room temperature is much higher than its viscosity when heated. This is because as the temperature increases, the honey becomes less viscous and flows more easily.

5. How does the change in viscosity with temperature affect the flow of fluids?

The change in viscosity with temperature affects the flow of fluids by altering their resistance to flow. Higher viscosity fluids are more resistant to flow and require more force to move, while lower viscosity fluids flow more easily. This can impact the efficiency of processes such as pumping liquids or the performance of lubricants in machinery.

Similar threads

Compare the conductance of an insoluble salt with soluble one
    • Introductory Physics Homework Help
Replies
2
Views
288
How Does Potential Energy Dissipation Affect Temperature in a Metal Cube?
    • Introductory Physics Homework Help
Replies
9
Views
870
I Trying to better understand what viscosity really is
    • Other Physics Topics
Replies
9
Views
16K
What happens as a gas expands?
    • Introductory Physics Homework Help
Replies
12
Views
5K
What happens to wavelength as temperature of air increases?
    • Introductory Physics Homework Help
Replies
3
Views
6K
Temperature change in different containers
    • Introductory Physics Homework Help
Replies
4
Views
2K
Isothermal, isobaric and adiabatic
    • Introductory Physics Homework Help
Replies
6
Views
1K
Temperature change of Water after dropping a ball into it
    • Introductory Physics Homework Help
Replies
10
Views
2K
Why did my water contract when exposed to rapid temperature change?
    • Introductory Physics Homework Help
Replies
7
Views
1K
Does levitation distance increase as Fg increase???
    • Introductory Physics Homework Help
Replies
1
Views
263

Hot Threads

Recent Insights

Back
Top