Calculate Degree of Dissociation & pH of 0.1M Propionic Acid

[shaiqbashir]

Hi Guys!


Dissociation constant of propionic acid at 25 degree celsius is 1.34 x 10^-5. Calculate the degree of dissociation and pH om 0.1M acid.

Ans: degree of dissociation=0.115
pH=2.93

now my dear friends i have calculated the pH already from the formual correctly. Now please tell me that how can i find this degree of dissociation because i don't know any formula in finding it out.PLease help.

 

[Borek]

dissociation percentage

 

[Blueshift5]

Hello there,

To calculate the degree of dissociation of propionic acid, we can use the formula:

α = √(K_a/[H+])

Where α is the degree of dissociation, K_a is the dissociation constant (1.34 x 10^-5 in this case), and [H+] is the concentration of hydrogen ions which can be calculated using the pH value.

So, for a 0.1M solution of propionic acid, the concentration of hydrogen ions can be calculated as [H+] = 10^-pH = 10^-2.93 = 6.72 x 10^-3 M.

Plugging in the values, we get:

α = √(1.34 x 10^-5 / 6.72 x 10^-3) = 0.115 or 11.5%

Therefore, the degree of dissociation of propionic acid in a 0.1M solution is 11.5%.

I hope this helps! Let me know if you have any further questions.