What is the hydrogen ion concentration in a 0.15 molar solution of acetic acid in water at 25 degrees C? Acetic acid is 1.3 % dissociated.
Set up an ICE chart.
.............CH3COOH ==> CH3COO^- + H^+
initial......0.15M.........0.........0
change........-x...........x.........x.
equil.......0.15-x.........x.........x.
So what is x? 0.15*0.013
To determine the hydrogen ion concentration in a solution of acetic acid, we need to consider its dissociation or ionization. Acetic acid (CH3COOH) dissociates partially in water, forming hydrogen ions (H+) and acetate ions (CH3COO-).
First, let's determine the initial concentration of acetic acid before dissociation. We have a 0.15 molar solution of acetic acid, which means 0.15 moles of acetic acid are present in 1 liter of solution (assuming the solution is not diluted).
Next, we need to calculate the concentration of hydrogen ions. Since acetic acid is only partially dissociated, the hydrogen ion concentration will be less than the initial concentration of acetic acid.
Given that acetic acid is 1.3% dissociated, this means that only 1.3% of the acetic acid molecules dissociate into hydrogen ions. To find the concentration of hydrogen ions, we can use the dissociation constant (Ka) for acetic acid.
The dissociation constant for acetic acid at 25 degrees Celsius is 1.8 x 10^-5.
Let's calculate the concentration of hydrogen ions:
1. Convert the percentage of dissociation to decimal form:
1.3% = 1.3 / 100 = 0.013
2. Calculate the concentration of hydrogen ions:
[H+] = (0.013) * (0.15 M)
= 0.00195 M
Therefore, the hydrogen ion concentration in the 0.15 molar solution of acetic acid is 0.00195 M at 25 degrees Celsius.