It gets always talked about the addition of a strong acid or strong base to a buffer... my question would be how to calculate the ph with the addition of a weak acid? Lets say the addition of acetic acid to a phosphate buffer
Hi Patrick, it can get complicated, but in short, the acid's proton would react with the more basic phosphate, which would effect the pH minimally. At the same time, you would create an acetate salt (such as sodium phosphate), which could react with the acetic acid (if any left in the solution) creating a buffer. If you add just a bit of acetic acid to the phosphate buffer, the pH will change minimally, because essentially you will have a small amount of acetate salt in the phosphate buffer. The calculation, however, can get complicated, since the acid do not dissociate fully. I hope this helps! :)
@@DrVChem Thx yea helped a lot. Would it be possible to calculate the H+ ions coming from the added acidic acid with the common formula for weak acids and add them to the acid term / subtract them from the base term of the Henderson hasselbach equation? (igonring the acetate buffer created)
you are so smart, thankyou very much
Awww ☺️ Thank you so much! I’m glad that the videos are helpful!
It really helped a lot.
Yay! I'm glad it helped! Please don't hesitate to ask if you have any questions! :)
It gets always talked about the addition of a strong acid or strong base to a buffer... my question would be how to calculate the ph with the addition of a weak acid? Lets say the addition of acetic acid to a phosphate buffer
Hi Patrick, it can get complicated, but in short, the acid's proton would react with the more basic phosphate, which would effect the pH minimally. At the same time, you would create an acetate salt (such as sodium phosphate), which could react with the acetic acid (if any left in the solution) creating a buffer. If you add just a bit of acetic acid to the phosphate buffer, the pH will change minimally, because essentially you will have a small amount of acetate salt in the phosphate buffer. The calculation, however, can get complicated, since the acid do not dissociate fully. I hope this helps! :)
@@DrVChem Thx yea helped a lot. Would it be possible to calculate the H+ ions coming from the added acidic acid with the common formula for weak acids and add them to the acid term / subtract them from the base term of the Henderson hasselbach equation? (igonring the acetate buffer created)
Thank you
You are welcome ☺️