What are the attractive forces in a neutral fluid?

In summary, the conversation discusses the relationship between heat and water temperature, particularly how temperature stops rising at 0C due to attractive forces between molecules. The concept of van der Waals forces is mentioned, which explains these intermolecular attractions. The question of how these attractive forces exist between neutral molecules is raised. It is also noted that van der Waals forces only apply to the gas state, while the questioner is interested in all states of matter. It is suggested that in the case of water, the polar nature of its molecules may play a role in these intermolecular forces.
  • #1
rogerk8
288
1
Hi!

I wonder about how for instance water temperature is changed with regard to applied heat.

You all know that if you take ice and heat it up temperture will climb until it reaches 0C.

When it reaches 0C it however stobs climbing in tempertaure regardless of how much heat you supply.

It is said that heat is needed to overcome the attractive forces of the molecules instead of just giving them higher speed (i.e Ek and thus temperature).

It is said that these attractive forces constitute a potential energy to be overcome before the molecules can move faster thus giving the fluid higher temperature, Ek.

I just wonder what these attractive forces are because as far I understand there is no attractive forces between neutral molecules.

And regardless of state (solid, liquid or vapour) neutral H20 is still the molecule in mind.

So where is the attractive forces?

Roger
 
Physics news on Phys.org
  • #2
rogerk8 said:
as far I understand there is no attractive forces between neutral molecules.

Look up "van der Waals forces".
 
  • #3
Van der Waal considers both the physical size of gas particles and "intermolecular attractions".

I have read this fantastic site: http://www.et.byu.edu/~rowley/ChEn273/Topics/Mass_Balances/Single_Phase_Systems/Van_der_Waals_Equation_of_State.htm

And it states that there are "intermolecular attractions".

But it never explains how or why.

So my question remains, how can there be intermolecular attractions between neutral molecules?

Roger
 
  • #4
Another thing, I am interested in all the states of matter.

Van der Waal only considers the gas state.

Roger
 
  • #5
I can't answer in general, but at least water is a polar molecule. Taken as a whole it is neutral, but it isn't made of neutral particles. Since the particles are separated, it has a dipole electric field. I forget a kot of chem, but I bet a lot of intermolecular forces are electric forces due to uneven electon sharing.
 
  • Like
Likes rogerk8

Related to What are the attractive forces in a neutral fluid?

1. What are the types of attractive forces in a neutral fluid?

The two main types of attractive forces in a neutral fluid are van der Waals forces and hydrogen bonding. Van der Waals forces are weak intermolecular forces between non-polar molecules, while hydrogen bonding is a stronger force between polar molecules that contain hydrogen atoms bonded to highly electronegative atoms.

2. How do attractive forces affect the behavior of a neutral fluid?

Attractive forces play a crucial role in determining the properties and behavior of a neutral fluid. These forces are responsible for the cohesion and surface tension of the fluid, as well as its ability to form droplets and adhere to surfaces.

3. Can attractive forces be stronger than repulsive forces in a neutral fluid?

Yes, attractive forces can be stronger than repulsive forces in a neutral fluid. This is especially true for fluids with strong hydrogen bonding, where the attractive forces can overcome the repulsive forces between molecules and allow for the formation of stable structures, such as water droplets.

4. How do temperature and pressure affect the strength of attractive forces in a neutral fluid?

Temperature and pressure can both influence the strength of attractive forces in a neutral fluid. As temperature increases, the kinetic energy of molecules also increases, which can weaken the attractive forces. On the other hand, increasing pressure can bring molecules closer together, making the attractive forces stronger.

5. Can attractive forces in a neutral fluid be manipulated?

Yes, attractive forces in a neutral fluid can be manipulated through various methods, such as changing the temperature, pressure, or the chemical composition of the fluid. Scientists can also use external fields, such as electric or magnetic fields, to manipulate the strength of attractive forces in a fluid.

Similar threads

I Trying to better understand what viscosity really is
    • Other Physics Topics
Replies
9
Views
16K
Dalton's atomic theory, Avogadro, and caloric theory
    • Chemistry
Replies
4
Views
2K
Temperature changes and degrees of freedom and intermolecular forces
    • Thermodynamics
Replies
16
Views
5K
Evaporation questions about saturation pressure
    • Mechanics
Replies
24
Views
5K
I Some questions about Cosmic Microwave Background radiation
    • Cosmology
Replies
13
Views
2K
Continuity Between Statistical Mechanics and Fluid Dynamics
    • Mechanics
Replies
2
Views
2K
B Exploring Nuclear Fusion: IEC Fusion Reactor Construction and Operation
    • High Energy, Nuclear, Particle Physics
Replies
19
Views
3K
Vapour pressure and volatility.
    • Biology and Chemistry Homework Help
Replies
1
Views
11K
Negative absolute temperatures
    • Thermodynamics
Replies
1
Views
1K
Is my summary of these subjects correct?
    • Other Physics Topics
Replies
0
Views
763

Hot Threads

Recent Insights

Back
Top