okay, An example to I'm saying over what ph range will in oxalic acid, H two, C 204 and a sodium oxalate. NHC 204 Solution work most effectively the acid association constant of oxalic acid is 6.0 times 10 to the negative, too. So when I say acid association constant, I'm just saying, K, now we're talking about the ph Range or, in this case, the buffer range, because here we have a weak acid and its conjugate base. Now you need to realize that buffers can't work at any pH. There is a range to their effectiveness, and you're just gonna simply say that a buffer works best when pH equals P K plus or minus one. That is the range of a buffer, plus or minus one. The P. K that is called our buffer range. So we're gonna do here is we're gonna say p k equals negative log of K A so equals negative log of 6.0 times 10 to the negative, too. And that is 1.22 So you're Ph is plus or minus that number, so you're gonna say 1.2 to minus one is 10.22 1.22 plus one is 2.22 So the range would be 0.22 to 2. This would be our buffer range. Within this range, this buffer is most effective. Okay, so the pH would have to be between 0.22 or 2.22 If it's anywhere outside that range, then this buffer will not be able to work. So that means a would be our answer. So just remember, a buffer works effectively within a buffer range, which is a simply p k plus or minus one. That's the pH range it'll work in. Now that we've attempted these two questions, guys, I want you to attempt to do the practice question I left on the bottom again. It involves. Are you able to manipulate the Henderson Hasselbach equation? And again, if you get stuck, don't worry about it. Just come back, take a look at look at my video to see how best I approach and explain the best way to get the answer. Good luck, guys.