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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: oddlysimplestars on February 13, 2020, 08:05:04 PM

Title: I have some questions about my Buffer lab
Post by: oddlysimplestars on February 13, 2020, 08:05:04 PM
I have to describe the reactions that occur when the NaOH was added to the salt solution, but the salt solution is not specified, so I'm assuming it is any salt solution, and I'll use NaCl. Would I be correct if I said that the NaOH and NaCl both dissociate into their ions, causing the pH to increase? 

 Also, I have to describe what happens when a few drops of NaOH are added to the acetic acid -
acetate buffer, and what happens when the last few drops are added, so when the phenolphthalein indicator in the solution changes colour. So the first drops of NaOH causes the pH to go up slightly but the buffer then reverses the reaction by releasing hydrogen ions into the solution from the unreacted CH3COOH molecules, causing the pH to return to neutral. So what is the difference when the last few drops are added? Is there simply not enough  unreacted CH3COOH molecules, so the pH goes up?

Also, would the formula for this reaction be
NaOH + CH3COOH → CH3COO-  + H2O


I'm sorry if this is too long or confusing, but thank you for taking the time to read! :)