Ionization of Strong Acids: Does Concentration Matter?

In summary, equilibrium is reached in a way in which an acid donates its proton to a water molecule, forming a hydronium ion. However, the hydronium ion can also donate the proton back to the conjugate base of the acid, which reproduces the acid molecule. This back and forth will continue until equilibrium is reached and both processes are continuing at equal rates.
  • #1
JonnyG
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I know that a "strong acid" is one that ionizes completely in water. For example, hydrochloric acid, sulfuric acid, nitric acid, etc are considered strong acids because they all completely neutralize. Now, this leads me to two questions:

1) Is the concentration of a strong acid irrelevant in determining whether or not it completely ionizes? So for example, would 95% sulfuric acid ionize completely?

2) This question is applicable only if the answer to the above question is no. So suppose that the concentration IS a determining factor in ionization %, even if the acid is strong. Would neutralizing the acid induce further ionization? Let me give a concrete example. Suppose we had 1 mole of concentrated hydrochloric acid. Suppose that at this concentration, 50% of the HCl ionized. Then 0.50 moles of HCl is ionized and the 0.50 moles exists in solution as molecular HCl. Now suppose we added 0.50 moles of NaOH. This completely neutralizes the 0.50 moles of ionized HCl, correct? So now we have, in solution, 0.50 moles of NaCL and 0.50 moles of HCl. Now, does more HCl ionize since the concentration of HCl has decreased? Does the NaCl in the solution effect how much further the remaining HCl ionizes? (if it does actually ionize)
 
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  • #2
Question 1: "Yes."
 
  • #3
Have you heard about equilibrium reactions? Equilibrium constants? If not, follow the Bystander answer. If not - there is a lot of chemistry that you have to learn yet.
 
  • #4
Borek said:
Have you heard about equilibrium reactions? Equilibrium constants? If not, follow the Bystander answer. If not - there is a lot of chemistry that you have to learn yet.

I have learned about different types of equilibrium. For example, every liquid has an equilibrium vapor pressure. I am guessing there is a type of equilibrium involved with my question? There is a chapter in my textbook that is titled "chemical equilibrium". I will be at that section within a couple of days. Maybe this section will answer my question for me? In any case, could you please give me a brief answer?
 
  • #5
Start here:

https://en.wikipedia.org/wiki/Chemical_equilibrium

In short: for an acid neutralizing H+ produced during neutralization will induce further dissociation, till the system gets to a new equilibrium. And in general there are no acids strong enough to be always 100% dissociated (although for some acids that's quite a good approximation), so dissociation is always an equilibrium process.
 
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  • #6
It seems to me that equilibrium is reached in the following way: the acid donates a proton to a water molecule, forming a hydronium ion. However, the hydronium ion can also donate the proton back to the conjugate base of the acid, which reproduces the acid molecule. This back and forth will continue until equilibrium is reached and both processes are continuing at equal rates.
 
  • #7
The only thing left for you to notice is that in both cases it is the same scheme - an acid donates its proton to a base. After the reaction what was an acid becomes a base (minus proton), what was a base becomes an acid (protonated).

You have just discovered what the Bronsted-Lowry acid and base are :wink:
 
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FAQ: Ionization of Strong Acids: Does Concentration Matter?

1. What is the definition of ionization of strong acids?

Ionization of strong acids refers to the process by which a strong acid, such as hydrochloric acid (HCl) or sulfuric acid (H2SO4), dissociates into its constituent ions (H+ and an anion) in an aqueous solution.

2. How does the concentration of a strong acid affect its ionization?

The concentration of a strong acid does not affect its ionization. Strong acids are completely dissociated in water, regardless of concentration. This means that a 0.1 M solution of a strong acid will have the same degree of ionization as a 1 M solution of the same acid.

3. Does the strength of a strong acid change with concentration?

No, the strength of a strong acid does not change with concentration. The strength of an acid refers to its ability to donate a proton, and this is determined by the chemical structure of the acid and not its concentration.

4. How does the ionization of strong acids compare to weak acids?

The ionization of strong acids is complete, meaning they completely dissociate into ions in solution. In contrast, weak acids only partially dissociate, meaning there will be a mixture of both the acid and its ions in solution. This is due to the difference in chemical structures and strengths between strong and weak acids.

5. Is there any benefit to using a higher concentration of a strong acid?

In terms of ionization, there is no benefit to using a higher concentration of a strong acid. However, a higher concentration may be beneficial in other aspects, such as increasing the rate of a reaction or reducing the amount of solvent needed for a reaction.

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