a solution of 2.5 M weak acid is .52% ionized. what is the Ka value of this acid?
ive been stuck on this one for a long time and cant figure out where to even start...if someone could walk me through this itd be great! thanks
If the solution is 0.52M and it is 0.52% ionized, then the ions are 0.52% of 2.5M; therefore, (H^+) = (A^-) = 0.0052*2.5 = about 0.013M
......HA ==> H^+ + A^-
So plug thes numbers into the Ka expression and solve for Ka.
(H^+) = 0.013M
(A^-) = 0.013M
(HA) = 2.5-0.013 = ?
Well, well, well, looks like you could use a little help with your chemistry problem. Don't worry, I'm here to turn that frown upside down! Let's break it down step by step, shall we?
First, you need to find the concentration of the ionized form of the acid. Since the solution is 0.52% ionized, that means only 0.52% of the acid has dissociated into ions. So, multiply 2.5 M by 0.52% (or 0.52/100) to find the concentration of the ionized form.
Next, we can use the fact that the weak acid is only partially ionized to set up an equilibrium expression. Remember that Ka represents the acid dissociation constant, so our expression will look something like this:
Ka = [H+][A-] / [HA]
Now, plug in the concentration of the ionized form (H+ and A-) and the initial concentration of the acid (HA) into the equilibrium expression.
Solve for Ka, and voila! You've got your answer.
I hope that explanation brought a smile to your face! If you need any more assistance, I'll be here juggling my chemical equations.
To find the Ka value of the weak acid, you need to use the expression for the percent ionization of a weak acid:
% ionization = (concentration of ionized acid / initial concentration of weak acid) * 100
In this case, you are given the initial concentration of the weak acid as 2.5 M and the percent ionization as 0.52%.
First, convert the percent ionization to a decimal:
% ionization = 0.52/100 = 0.0052
Now, let x represent the concentration of the ionized acid. Since the weak acid is only partially ionized, the concentration of the un-ionized acid will be (2.5 - x).
Next, substitute the given values into the percent ionization expression:
0.0052 = (x / 2.5) * 100
Now, divide both sides of the equation by 100 to eliminate the percentage:
0.0052/100 = x / 2.5
Simplifying this equation gives:
0.000052 = x / 2.5
Next, multiply both sides of the equation by 2.5 to isolate the concentration of the ionized acid:
0.000052 * 2.5 = x
x ≈ 0.00013 M
So, the concentration of the ionized acid is approximately 0.00013 M.
Finally, you can calculate the Ka value using the equation:
Ka = (x^2) / (initial concentration - x)
Ka = (0.00013^2) / (2.5 - 0.00013)
Ka ≈ 6.1 × 10^-10
Therefore, the Ka value of the weak acid is approximately 6.1 × 10^-10.
To find the Ka value of the weak acid in this problem, we can use the percent ionization and the initial concentration of the acid.
The percent ionization tells us the fraction of the initial concentration that dissociates into ions. In this case, the acid is only 0.52% ionized. This means that 0.52% of the initial concentration has dissociated to form ions, while the rest remains undissociated.
The initial concentration of the acid is given as 2.5 M (Molarity), which means that 2.5 moles of the acid are dissolved in 1 liter of solution.
To start, we need to calculate the concentration of the dissociated ions. Since the acid is only 0.52% ionized, the concentration of the dissociated ions is 0.52% of the initial concentration.
Concentration of dissociated ions = (0.52% / 100) * 2.5 M
Next, we need to calculate the concentration of the undissociated acid. Since the acid is only partially ionized, the concentration of the undissociated acid is equal to the initial concentration minus the concentration of the dissociated ions.
Concentration of undissociated acid = 2.5 M - (0.52% * 2.5 M / 100)
Now that we know the concentration of the dissociated ions and the undissociated acid, we can set up the equation for the dissociation of the weak acid:
HA ⇌ H+ + A-
The expression for the acid dissociation constant Ka is:
Ka = [H+][A-] / [HA]
where [H+] is the concentration of the H+ ions, [A-] is the concentration of the A- ions, and [HA] is the concentration of the undissociated acid.
Plugging in the values we calculated earlier:
Ka = ([H+][A-]) / [HA]
= (Concentration of dissociated ions)^2 / Concentration of undissociated acid
Finally, substitute the calculated concentrations into the equation and calculate the Ka value.
Please note that in order to calculate the exact Ka value, you need to know the exact concentration of the dissociated ions and undissociated acid. The values provided in this explanation are for illustration purposes only.