Hey, everyone. So here we're going to say that oxy aids represent covalent compounds containing the hydrogen ion bonded to a poly atomic ion containing oxygen. So here, if we wanna take a look at two typical typess of oxy acids, let's say we're um reacting H plus with your nitrite ion which is no two minus the numbers and the charges are the same. So when they combine, this gives me HNO two which is nitrous acid, it is a covalent compound begins with the hydrogen and it is composed of a poly atomic ion containing oxygen. Now, let's say that we react to H plus with our soft fight ion. The numbers in the charges are different when this happens. They crisscross one comes here. Two comes here. Don't worry about the charges. We just cross cross the numbers. This gives us H two. So three which is sulfurous acid. This is also an example of an oxy acid. So just remember an oxy acid is just an acid with the presence of oxygen.
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Oxyacids Example
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Which of the following represents the possible structure of an oxy acid. So if we take a look at the first one, the first one is sodium nitrate, there is no H plus ion involved within the structure. So it can't represent an acid, let alone an oxy acid. For the next one, it's covalent. It has hydrogen in the beginning. So it is an acid, it has the presence of oxygen. So it is an oxy aid here. This one is called formic acid. By the way, CC is not an acid because in this one, it represents an ionic base. It is a positive metal cion potassium ion connected to hydroxide ion which is a basic anion. OK. So this is a base. And then finally, the last one, it is covalent, only nonmetals together, it starts with a hydrogen. So it is an acid but it has no oxygen. So it is a binary acid, not an oxy aid. So the only one that's an oxy acid here is option B
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Oxyacid Strength Rule
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Now that you know how to identify an oxy aid. Let's talk about how do we identify if an oxy acid or weak or strong? So here to do that, we rely on the oxy aid strength rule and it says if a neutral oxy acid has two or more oxygens than hydrogens, then the oxy acid is a strong acid. Now, let's take a look at these three oxy aids before us. So first, we have HCLO three here. How many oxygens does it have? It has three. How many hydrogens does it have? It has one when you subtract them, you have two oxygens left. So we have, we've met the requirement of having at least two oxygens more than hydrogens. So this is strong. Next hocn is an oxy acid, we're gonna say here we have one oxygen, one hydrogen, we have no oxygens remaining. We don't meet the requirement of having at least two more oxygens and hydrogens. So this is weak. And then finally, the last one, we have two oxygens, we have seven plus one is eight hydrogens. We definitely don't have more oxygens than hydrogens. So this is weak. Now, of course, there will be exceptions. Here are two exceptions. And the good thing is that it's just these two, we have oxalic acid, which is H two C, 204 and we have io acid, which is hio three. If we did the math, we'd have two more oxygens than hydrogens. But they're both still considered weak oxy acids. And that's because they're non hydrogen elements. In this case, carbon and iodine have low electron negativities. So this is just the simplest way to think about why there are exceptions to the rule. All right. So just remember if a neutral oxy acid has two or more oxygens than hydrogens, then it can be a strong acid. The exceptions to this are oxalic acid and ionic acid. So just remember to do the math and you could determine which is weak and which is strong.
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Oxyacids Example
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Which of the following represents a strong oxy acid. Remember based on our rule, we're gonna say if a neutral oxy aid has two or more oxygens than hydrogens, then it is a strong acid D is out because D is not neutral, it has a charge. So we have to look at ABC and E when we do the math, we're gonna have two oxygens here minus one hydrogen gives us only one oxygen left doesn't meet the requirement. Here, we have two oxygens. We have four hydrogens. We definitely don't have any oxygens left. This one here, we have one oxygen, one hydrogen and that the zero doesn't work. E is our answer because here we have three oxygens minus one hydrogen. We have the minimum requirement of two oxygens more than hydrogen. So this would be our strong oxy acid. This is Bromma acid. All right. So just keep in mind the rule that we talked about when it comes to oxy acid strength. And remember are two exceptions of oxalic acid and tic acid. If you can remember that you'll know how to identify a weak oxy acid versus a strong oxy acid.
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Comparing Oxyacid Strength
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So up to this point, we've learned how to identify oxy aids. We've learned to determine which one is weak and which one is strong. And now we're gonna go over comparing them to one another. We're gonna say when comparing the strengths of oxy aids, it's all in the oxygens. We're gonna say, do they have different numbers of oxygen remaining or do they have the same number of oxygens remaining? Well here, if they have a different number of oxygens remaining, we're going to say that more oxygens remaining equals more acidic. If we take a look here, we have as our examples, we're gonna hypo iota acid versus iota acid. When you do the math, this one has nothing left and this one here has one oxygen left iota acid has more remaining oxygens, therefore, it's stronger. So this would be our stronger oxy acid. Now, if the difference between oxygen and hydrogen are the same that we're gonna say here, the higher the electronegativity of the central element than the more acidic, if you were to figure out the remainder of oxygens left, for both of them, you get the same result, one oxygen left. So then you have to look at the non hydrogen element here. We're comparing sulfur versus selenium. They're both in group six A. So we have oxygen sulfur selenium. Remember as we had up a group, your electron negativity is increasing. So sulfur is more electron than uh selenium. Therefore, h two. So three which is sulfurous acid is more acidic. So again, the way you're able to compare different oxy acids to each other, it's all in the number of oxygens remaining. Do they have different number of oxygens remaining or do they have the same number of oxygens remaining? Knowing that is key to comparing them to one another.
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Oxyacids Example
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Rank the following oxy aids in terms of increasing acidity, right. So, since they're all oxy aids, we're gonna first look at the difference in number of oxygens and hydrogens for each one. So here we do three oxygens minus one hydrogen. So we have two oxygens left here. This has three oxygens left. When we do three minus one, that's two oxygens left here. This would have three oxygens left and this would have zero oxygens left. When you do number of oxygens minus number of hydrogens, we're doing it in terms of increasing acidity. So we wanna do weakest. First up the strongest here. Option five would be the weakest since it has the least number of oxygens remaining. Next, we look at the ones that have two oxygens remaining a piece. 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 that we rely on the electronegativity of the non hydrogen element. Here, chlorine versus bromine, the more electron, the non hydrogen element, the more acidic, the oxy acid here, chlorine is more electron 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 non hydrogen element. Again, it's chlorine versus bromine, chlorine is more electron. Therefore, hclo four, 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.