About 13% of the acid in a 0.10M solution of a weak acid dissociates to form ions.
What is the H3O+ concentration?
What is the OH- concentration?
What is the pH of the solution?
Well, well, well, we have some acid-dissociation business over here! Let's break it down and have some fun with these questions!
First off, if only 13% of the acid dissociates, we can assume that 87% of our acid is still hanging out together, like three amigos in a bottle.
So, to find the concentration of H3O+ (the hydronium ions), we simply multiply the initial concentration of the acid by 13%. That's like squeezing out 13% of the juice from an orange. Mmm, citrusy science!
Hence, the H3O+ concentration would be 0.10M * 0.13 = 0.013M.
Now, since every acid needs a buddy, for every H3O+ that forms, an OH- will show up to the party. It's like a balancing act, where one goes up, the other comes down, just like a see-saw on the playground of chemistry.
So, if we have 0.013M of H3O+, we also have 0.013M of OH-! They're like the Yin and Yang of chemistry, always keeping each other in check.
Lastly, to find the pH of the solution, we'll have a bit of fun with some math. The pH is basically the negative logarithm (base 10) of the H3O+ concentration.
So, pH = -log(0.013) = 1.88. Ta-da!
There you have it! H3O+ concentration of 0.013M, OH- concentration of 0.013M, and a pH of 1.88. Chemistry with a sprinkle of clown humor, just for you!
To find the answers to these questions, we need to use the concept of the ionization constant and the equation of the weak acid dissociation.
Let the weak acid be represented as HA, and its dissociation equation can be written as follows:
HA ⇌ H+ + A-
Given that 13% of the acid dissociates, we can assume that the concentration of H+ ions will be equal to 13% of the initial acid concentration.
Now let's calculate the H3O+ concentration, OH- concentration, and the pH of the solution step-by-step.
Step 1: Calculate the H3O+ concentration:
As mentioned above, the concentration of H+ ions will be equal to 13% of the initial acid concentration. Therefore, the concentration of H3O+ ions is also 13% of the initial acid concentration.
H3O+ concentration = 0.13 * 0.10 M
H3O+ concentration = 0.013 M
Step 2: Calculate the OH- concentration:
The dissociation of water produces an equal concentration of H3O+ and OH- ions in pure water. However, in the presence of an acid, the concentration of OH- ions decreases.
Since the solution is acidic (weak acid), we can assume that the OH- concentration will be very low compared to the H3O+ concentration.
In this case, the OH- concentration can be approximated as negligible.
Step 3: Calculate the pH of the solution:
The pH of a solution is defined as the negative logarithm (base 10) of the H3O+ concentration.
pH = -log[H3O+]
pH = -log(0.013)
pH ≈ 1.89
So, the H3O+ concentration is 0.013 M, the OH- concentration is negligible, and the pH of the solution is approximately 1.89.
To find the answers to these questions, we need to use the dissociation constant (Ka) of the weak acid. The dissociation constant tells you the extent to which a weak acid dissociates in water.
Let's assume that the weak acid is represented by the formula HA, and that it dissociates as follows:
HA ⇌ H+ + A-
Given that 13% of the acid dissociates, it means that the concentration of H+ ions formed is 13% of the initial concentration of the weak acid, or 0.13 times the initial concentration.
1. To find the H3O+ concentration:
Since H+ ions combine rapidly with water to form H3O+, the H+ concentration is equal to the H3O+ concentration. Therefore, the H3O+ concentration is 0.13 times the initial concentration of the acid, or 0.13 * 0.10 M = 0.013 M.
2. To find the OH- concentration:
Since water is neutral, the product of the H3O+ concentration and the OH- concentration is a constant value, known as Kw (the ionization constant for water). At 25°C, Kw = 1.0 x 10^-14 mol^2/L^2.
Using this information, we can calculate the OH- concentration. Since [H3O+][OH-] = Kw, we can rearrange the equation to get [OH-] = Kw / [H3O+].
Given that Kw = 1.0 x 10^-14 mol^2/L^2 and [H3O+] = 0.013 M, we can now find the OH- concentration, which is:
[OH-] = (1.0 x 10^-14 mol^2/L^2) / (0.013 M) = 7.69 x 10^-13 M.
3. To find the pH of the solution:
The pH is a measure of the acidity of a solution and is defined as the negative logarithm (base 10) of the H3O+ concentration.
Using the H3O+ concentration we calculated earlier (0.013 M), we can find the pH as follows:
pH = -log10[H3O+]
pH = -log10(0.013)
pH ≈ 1.89
Therefore, the H3O+ concentration is 0.013 M, the OH- concentration is 7.69 x 10^-13 M, and the pH of the solution is approximately 1.89.
If the acid is 0.1M and it dissociates 0.13 fraction then 0.1 x 0.13 = 0.013 = (H3O^+)
pH = -log(H3O^+)
pH + pOH = pKw = 14. You have pH and pKw, solve for pOH.