[Creflo]

I'm assuming the ester is incorrect, but I don't see how it's a carboxyl group as there is no H attached to the O (the Oxygen has an extra lone pair giving it a negative charge right?) I know this is simple, but any help would be appreciated.    UPDATE: I'm assuming that since COO- is carboxylate that it is indeed a carboxyl group?



UPDATE: ok so apparently I was right, it is a carboxyl group, I would just delete this post if I could but whatevs. Sorry I'm so dumb!

[Yggdrasil]

A carboxyl group (also known as a carboxylic acid) can exist as in a protonated form R-COOH and a deprotonated form R-COO^- depending on the pH of the solution.  This is similar to the amino group which also undergoes acid-base chemistry, and a primary amine can either be protonated (R-NH₃⁺) or deprotonated (R-NH₂).

[Creflo]

I figured it out. But thank you for the reply Yggdrasil!

[Babcock_Hall]

I usually call the conjugate base form a carboxylate group, and the conjugate acid form a carboxylic acid group.