Degree of dissociation accurately defined

In summary, the degree of dissociation is a fraction of the substance that dissociated. It doesn't depend on the amount of substance dissolved.
  • #1
Entanglement
439
13
Is the degree of dissociation the value of

Alpha when the dissociation begins with 1 mole of the solute, or is it alpha when the solute is 1 mole at equilibrium,
There isn't a difference since I'm talking about very weak electrolytes but I want to know the accurate answer.
 
Chemistry news on Phys.org
  • #2
Degree of dissociation is a fraction of substance that dissociated, and it doesn't depend on the amount of substance dissolved.
 
  • #3
Borek said:
Degree of dissociation is a fraction of substance that dissociated, and it doesn't depend on the amount of substance dissolved.
It's said on Wikipedia that is the value of dissociated moles per 1 mole,

It is meant one mole at equilibrium or when the dissociation begins with that 1 moles ?
 
  • #4
I don't care about what wikipedia says. Degree of dissociation is a fraction of the substance that dissociated. You start with n moles, m moles dissociate, degree of dissociation is m/n.
 
  • #5
Borek said:
I don't care about what wikipedia says. Degree of dissociation is a fraction of the substance that dissociated. You start with n moles, m moles dissociate, degree of dissociation is m/n.
Ok, m/n will give the value of m when n is 1, there's no contradiction
 
  • #6
No contradiction, but a lousy thinking. Ratio doesn't require referring to the amount of substance.
 
  • #7
Borek said:
No contradiction, but a lousy thinking. Ratio doesn't require referring to the amount of substance.
"n moles" is the number of moles at equilibrium or the number of moles that the dissociation starts with ?
 
  • #8
The degree of dissociation can be defined independently of equilibrium.
E.g., you could measure it as a function of time after bringing an undissociated substance into a solvent.
 
  • #9
Borek said:
You start with n moles, m moles dissociate

ElmorshedyDr said:
"n moles" is the number of moles at equilibrium or the number of moles that the dissociation starts with ?

Perhaps it is time you start paying attention to what you read.
 
  • #10
Borek said:
Perhaps it is time you start paying attention to what you read.
I'm sorry, thanks a lot for you help
 
  • #11
I have a question about the ionic product of water

How is Kw = [ H ] [ OH ] = 10^-14 mole/ liter derived.
 
  • #12
It is not derived, it is determined experimentally.

Please start new threads for new questions.
 

1. What is the degree of dissociation and why is it important in scientific research?

The degree of dissociation is a measure of the extent to which a compound breaks apart into its constituent parts in a given chemical reaction. This information is crucial in understanding the behavior and properties of chemical compounds, as well as predicting their reactions and interactions with other substances.

2. How is the degree of dissociation accurately defined and calculated?

The degree of dissociation is defined as the ratio of the number of dissociated molecules to the total number of molecules initially present in a reaction. It can be calculated by dividing the concentration of dissociated molecules by the initial concentration of the compound and multiplying by 100%.

3. Can the degree of dissociation change during a reaction?

Yes, the degree of dissociation can change during a reaction as the concentration of reactants and products changes. It is also dependent on factors such as temperature, pressure, and the presence of catalysts.

4. How does the degree of dissociation affect the equilibrium constant of a reaction?

The degree of dissociation is directly related to the equilibrium constant of a reaction. A higher degree of dissociation means a higher equilibrium constant, indicating that the reaction favors the formation of products. Conversely, a lower degree of dissociation results in a lower equilibrium constant, indicating that the reaction favors the formation of reactants.

5. Is the degree of dissociation the same as the reaction yield?

No, the degree of dissociation and reaction yield are not the same. The degree of dissociation represents the extent to which a compound breaks apart, while the reaction yield is the amount of product obtained from a reaction. The two values may be related, but they are not interchangeable.

Similar threads

Can Sodium Carbonate be Produced Using a DIY Setup?
    • Chemistry
Replies
8
Views
2K
Calculating Percentage of Dissociated N2O4 Molecules: Vapour Density Question
    • Biology and Chemistry Homework Help
Replies
1
Views
1K
Onsanger and Stefan-Maxwell Equations
    • Chemistry
Replies
9
Views
868
Diffusion, Migration and Einstein Equation
    • Chemistry
Replies
13
Views
1K
Can a 0.1M Buffer Solution Be Prepared Using Henderson-Hasselbalch Equation?
    • Chemistry
Replies
1
Views
2K
Calculate ionic concentration
    • Biology and Chemistry Homework Help
Replies
3
Views
1K
Internal Resistance of the Battery - Ohmic Resistance
    • Chemistry
Replies
21
Views
2K
Calculating pKa when pH is known
    • Chemistry
Replies
2
Views
7K
SI engine combustion. CO2 dissociation?
    • Chemistry
Replies
1
Views
4K
Why doesn't a weak acid/base act as a buffer on its own?
    • Chemistry
Replies
4
Views
7K

Hot Threads

Recent Insights

Back
Top