Based on their compositions and structures and on conjugate acid–base relationships, select the stronger base in each of the following pairs: (b) PO43- or AsO43-

Video transcript

Hi everyone for this problem. It reads considering the structure composition and conjugate acid based relationships identify the weaker base between the chlorine and ion and a bromine and ion. Okay, so we want to identify the weaker base. So let's go ahead and get started. The first thing that we're going to want to do when we're thinking about a problem like this is we can see that these are two conjugate bases that are derived from two acids. So we'll start by finding the two acids and we can do that by adding a proton to the conjugate base. Okay, so we have are conjugate base, a chlorate, an ion and a bromine. Eight an ion when we add a proton, this is going to result in an acid for both. And so for our first one we're going to get chlor IQ acid. And for our second one we're going to get moronic acid. Okay, so now that we know what acids these conjugate bases are derived from, we can see that they come from two halogen oxy acids. And for halogen oxy acids, strength increases with the number of oxygen atoms. Residents, residents or electro negativity of the central atom. Okay, so for our central atoms we can see we have corinne and we have bro mean, Okay, and so we can say that acid strength increases with the electro negativity of the central atom. So out of these two we can see that chlorine is more electro negative than bruning. So what that means is our our cleric acid is going to be stronger. This is going to be the stronger acid. Okay, so now that we know which one is the stronger acid, the strength of the conjugate base varies inversely with the strength of the acid. Okay, so what that means is the stronger the acid, the weaker the conjugate base. And I'll write conjugate base as C. B. Okay, so the stronger acid we said is our cleric acid, which means the weaker base is going to be our chlorate an ion. So the answer for this question because we identified the stronger acid, the stronger acid is going to have the weaker conjugate base. So our chlorate and ion is the weaker base. Okay, so that's the answer to this problem. I hope this was helpful.