Which functional groups can act as acids?

Question

Accepted Answer

Welcome back, everyone. Which of the following functional groups is most likely to act as a base. And a chemical reaction. Choice. A states ketone, choice B state carboxylic acid, choice, C state amine and choice D states alcohol. Let's recall that according to the Bronte Lowry definition, an acid is going to be a substance that donates H plus or a proton and a base is going to be a substance that accepts a proton. According to our Lewis definition, we have a base which can act as an electron pair donor and an acid which will act as an electron accept her electron pair acceptor. So beginning with choice, a, a key tone recall that in a ketone, we have a carbon chain bonded to a carbon which is sharing a pi bond to an oxygen atom or double bond. And we also have that carbon being bonded to another carbon chain. So as a whole, this represents our ketone functional group. Now, the only way that our atoms in this ketone can act as an electron pair donor is via our oxygen, which does have a set of two lone pairs on itself. However, they will only or it will only donate its electron pair if we have a very electro py reactant. So on its own, our ketone is not going to be able to donate any protons or donate any electrons because it's pretty stable. So let's rule out choice a and move on to choice. B carboxylic acid recall that for a carboxylic acid, we have a carbon chain bonded to a carbon or carbon within a Carboni rather And that carbonyl carbon is bonded to a hydroxyl group. Now, due to the fact that our Carboni acts as an electron withdrawing group because it's able to have its electron negative oxygen pull the electrons closer to oxygen. And also is able to have that net negative inductive effect because of that, that weakens our proton in our hydroxyl group. Meaning our hydroxyl group, hydroxyl group is less stable and we're able to donate a proton more easily because of that. So this means that we have an acidic proton in our hydroxyl group for our carboxylic acid. So choice B, carboxylic acid is most likely to act as an acid due to this acidic proton in the hydroxyl group. So let's rule out choice B because we again want the compound or functional group that will most likely act as a base in a chemical reaction. Moving on to choice C, we have an immune recall that our immune functional group consists of an amino group where we have nitrogen. It can have a bond to two hydrogens and then a lone pair on itself. This lone pair on nitrogen allows for nitrogen to be able to accept a proton. So it's going to act as a Bronte Lowry base. And thus, we can confirm that to C amine will act as a base in a chemical reaction. So let's place a check mark by choice C and move on to choice. D alcohol recall. Our alcohol group is characterized by our hydroxyl group. O h. Now a hydroxyl group, as we saw in carboxylic acid can only act as an acid or have an acidic proton if we have the presence of another group being an electron withdrawing group like a carbonyl. However, on its own, the hydroxyl in alcohol is going to have or going to be pretty stable on its own. So that means that our oxygen in this hydroxyl group is also most likely not going to want to donate any electron pairs, which would be on oxygen, meaning it won't act as a base either. So let's rule out choice D and this leaves us with choice C I mean, as our final answer as a functional group that is most likely to act as a base and a chemical reaction due to the fact that our immune group has an electron pair that is available to accept a proton. So choice C. Amin is our final answer. I hope this made sense and let us know if you have any questions?

Struggling with General Chemistry?

Which functional groups can act as acids?

Watch next

Functional Groups in Chemistry practice set