Rank the following oxyacids in terms of increasing acidity. Alright, so since they're all oxy acids, we're going to first look at the difference in number of oxygens and hydrogens for each one. So here we do 3 oxygens -1 hydrogen. So we have two oxygens left here. This has three oxygens left. When we do 3 -, 1, that's two oxygens left here. This would have three oxygens left, and this would have 0 oxygens left.

When you do number of oxygens minus number of hydrogens, we're doing it in terms of increasing acidity, so we want to do weakest first, up to strongest here. Option five will be the weakest since it has the least number of oxygens remaining. Next, we look at the ones that have two oxygens remaining apiece. Now, how do we determine which one is stronger?

Remember when the number of the difference between the number of oxygens and hydrogens is the same then we rely on the electronegativity of the non hydrogen element, Here chlorine versus bromine. The more electronegative the non hydrogen element, the more acidic the oxy acid. Here, chlorine is more electronegative than bromine, so that means that three would be less acidic than one.

And then we do the same thing with two and four. Again, the number of the difference between number of oxygens and hydrogens is the same. It's three. So look at the electronegativity of the nonhydrogen element. Again, it's chlorine versus bromine. Chlorine is more electronegative, therefore HCL₄, which is perchloric acid, is stronger. So that would mean two and then four would be the strongest.

So this would be the correct order in terms of increasing acidity when we're going from the weakest acid to the strongest oxy acid from the list provided.