What is the ionization constant for a weak acid HA that is 1.60% ionized in 0.095M solution?
........HA ==> H^+ + A^-
I......0.095...0.....0
So (H^+) = (A^-) = 0.095*0.016
Substitute into Ka expression and solve for Ka.
Well, if HA is only 1.60% ionized, I guess you could say it's having a bit of an identity crisis. It's like HA thinks to itself, "Am I an acid, or am I not? Who knows?" But don't worry, I'm here to help you figure it out.
To find the ionization constant (Ka) for a weak acid, you can use the equation:
Ka = ([H+][A-]) / [HA]
Since HA is only 1.60% ionized, we can assume that the concentration of [HA] left is 98.40% (100% - 1.60%). So, the concentration of [HA] would be:
[HA] = (98.40 / 100) * 0.095M
Next, let's assume that the percentage ionization is equal to the concentration of [H+] and [A-] (since [HA] is decreasing). So, [H+] and [A-] would both be 1.60% of 0.095M.
[H+] = [A-] = (1.60 / 100) * 0.095M
Now, let's plug these values into our Ka equation:
Ka = ((1.60 / 100) * 0.095M) * ((1.60 / 100) * 0.095M) / ((98.40 / 100) * 0.095M)
And after doing the math, you'll find the ionization constant (Ka) for HA. Just remember, even if HA is a bit unsure of its acid identity, you can always count on humor to make things a little less confusing!
To find the ionization constant (Ka) for a weak acid, we need to use the equation for percent ionization:
percent ionization = (ionized concentration / initial concentration) * 100
In this case, the percent ionization is given as 1.60%, and the initial concentration is 0.095 M. We are trying to find the ionized concentration.
Let's assume the ionized concentration is x.
Using the equation, we can write:
1.60 = (x / 0.095) * 100
Now, let's solve for x:
1.60 * 0.095 = x * 100
0.152 = 100x
x = 0.00152
So, the ionized concentration is 0.00152 M.
Now, we can calculate the ionization constant (Ka) using the equation:
Ka = (ionized concentration)^2 / (initial concentration - ionized concentration)
Plugging in the values:
Ka = (0.00152)^2 / (0.095 - 0.00152)
Ka = 0.00000231 / 0.09348
Ka ≈ 2.47 x 10^-5
Therefore, the ionization constant (Ka) for the weak acid HA is approximately 2.47 x 10^-5.
To determine the ionization constant (Ka) for a weak acid, we first need to know the concentration of the acid in solution and the percent ionization.
Given:
Concentration of weak acid (HA) in solution (C) = 0.095 M
Percent ionization (α) = 1.60%
The percent ionization is defined as the ratio of the concentration of ionized acid ([A-]) to the initial concentration of the acid ([HA]) multiplied by 100:
α = ([A-] / [HA]) * 100
Since we know the percent ionization, we can rearrange the equation to solve for the concentration of ionized acid:
([A-] / [HA]) = α / 100
Now, let's substitute the given values into the equation and solve for the concentration of ionized acid:
([A-] / [HA]) = 1.60 / 100 = 0.016
Now, we can express the concentration of ionized acid ([A-]) in terms of the concentration of weak acid ([HA]). Let's assume that x is the concentration of ionized acid. Therefore, the concentration of un-ionized acid ([HA]) can be expressed as (C - x).
([A-] / [HA]) = x / (C - x)
Substituting the known values:
0.016 = x / (0.095 - x)
To further simplify the equation, divide both sides by 0.095:
0.016 / 0.095 = x / (0.095 / 0.095 - x / 0.095)
0.168 = x / (1 - x / 0.095)
Let's cross-multiply to eliminate the fraction:
0.168 * (1 - x / 0.095) = x
0.168 - 0.168 * (x / 0.095) = x
Now, solve the equation for x:
0.168 - 0.168x/0.095 = x
0.168 * 0.095 - 0.168x = x
0.016 - 0.168x = x
0.016 = 1.168x
x ≈ 0.0137 M
Now that we have the concentration of ionized acid ([A-]), we can calculate the concentration of un-ionized acid ([HA]) by subtracting x from the initial concentration (C):
[HA] = C - x = 0.095 M - 0.0137 M = 0.0813 M
Finally, we can calculate the ionization constant (Ka) using the formula:
Ka = ([A-] * [H+]) / [HA]
Since [A-] is approximately equal to x and [H+] can be assumed to be equal to [A-], we can substitute the values:
Ka ≈ (0.0137 * 0.0137) / 0.0813
Ka ≈ 0.002301 / 0.0813
Ka ≈ 0.0283