Ionic Salts (Simplified) - Online Tutor, Practice Problems & Exam Prep

Salts are ionic compounds formed from the neutralization of acids and bases, resulting in water and a salt. The salt consists of a cation (positive ion) and an anion (negative ion). Cations can be classified into transition metals, main group metals, and positive amines, with specific charge requirements determining their acidity or neutrality. Anions are assessed by adding H⁺ to determine if they form weak or strong acids, influencing their basicity. Understanding these concepts is crucial for predicting the behavior of salts in solutions.

Ionic Salts (Simplified) Concept 1

Hey guys, in this brand new video, we're going to take a look at salts. So what we should realize here is whenever we have an acid or base neutralizing one another, we're going to usually form water as well as a second product. We call this second product a salt. And let's think of a simple basic type of acid-base reaction. Let's think of hydrochloric acid. Our products here are going to be HCl. HCl is made up of H⁺ and Cl^-, and NaOH is made up of Na⁺ and OH^-. Opposites attract. This positive and this negative are now attracted together. Whenever you have an H⁺ and OH^- combining, you form water. Now, the Na⁺ and Cl^- will be attracted to one another, and they give us NaCl. We're going to say NaCl is our salt. It's basically the ionic product that results from the neutralization between an acid and a base. Now, we're going to say that this salt here, which is made up of Na⁺ and Cl^-, can make our solution acidic, basic, or neutral depending on the rules that we're going to see in a few seconds from these two ions. That's the whole purpose of this section. So remember, we're going to have to learn that salts are just ionic compounds. They're made up of a positive ion called a cation and a negative ion called an anion. Based on certain properties, these ions can be acidic, basic, or neutral.

So, let's take a look at it. We're going to say here, if we're taking a look at our cations, we're going to break down our cations into basically three categories. We have our transition metals, we have our main group metals, and then we have our positive amines. Now remember, on your periodic table, the transition metals are the ones that are found within the pit. And remember, our main group metals are just group 1a, 2a, 3a, and 4a metals. And then our positive amines, remember an amine is a compound that has nitrogen and hydrogen or carbon, hydrogen, and nitrogen.

Let's look over the first section. The rule says if your transition metal has a charge of plus 2 or higher, it's going to be acidic. And we're going to say if the charge is less than plus 2, then it's going to be neutral. Let's think of an example here. Let's say we have Zinc Chloride and then we have Silver Bromide. Now, remember, zinc is always plus 2, so when this thing breaks up into its ions, these are the ions we're going to create. Now, zinc is a transition metal. It meets the requirement, it meets the minimum of a plus 2 charge. And because it meets the minimum of a plus 2 charge, it's going to be acidic. Now, silver bromide, when it breaks up, it's going to break up into Ag⁺ plus Br^-. Now, technically, if you remember your solubility rules, silver bromide is insoluble, shouldn't break up. But we're just saying theoretically, if it did break up. Here, it's a transition metal. It doesn't meet the requirement. It has to be plus 2 or higher. This is only plus one, so instead of being acidic, it would be neutral. Alright, so for each of these rules that we're going to go over, if they meet requirements of them, they could be acidic or basic. If they don't meet that requirement, that means they're automatically going to be neutral.

Ionic Salts (Simplified) Concept 2

Now, if we go to the next one, we're going to say if your main group metal has a charge of plus 3 or higher, then it's going to be acidic. If it doesn't meet that minimum requirement of plus 3, it's going to be neutral. So if we have silver on the aluminum acetate, and remember, we'll only focus on the metals right now. We'll learn about what we do with the negative ions in a few minutes. So we have aluminum acetate here, and then we have barium oxide. Remember, this will break up into Al³⁺ and we know it's 3 positive because aluminum is in group 3A. And don't worry about acetate for now; we'll talk about how we look at that in a few minutes. So, aluminum is a main group metal. It meets the minimum requirement of plus 3, so it's going to be acidic. Barium oxide, barium is in group 2A, so it's Ba²⁺. Oxide is in group 6A, so it's O^2-. This right here is a main group metal, but it doesn't meet the minimum requirement of plus 3. And because of that, it'll be neutral; it won't be acidic. So remember, transition metals, the ones in the pit, have to be plus 2 or higher. But main group metals have to be plus 3 or higher. If they meet the requirements, then they're acidic. If they don't meet those requirements, then they're going to be neutral.

Ionic Salts (Simplified) Concept 3

Now, positive amines are acidic. So, let's think of some examples here. We could have NH₄Br, We could have CH₃NH₃Cl. We could have C₆H₅ NH₃NO₂, all different examples. What you should realize here is, you just have to think of it like this. You can say that this first compound could be an amine. But what's messing it up? That bromine is messing it up. That one element there signifies that we have a salt, so you should know to break it up into its ions. So this breaks up into NH₄⁺, this breaks up into Br^-. We have a positive amine, so therefore that amine is automatically acidic. So remember, just tell yourself, it could be an amine, it could fit either this description or this description, but there's something that's interfering with it. What's that one thing? It's usually going to be at the end and it's going to be a negative anion. So just break it up into its 2 ions. You'll have your positive amine, you'll have your negative ion, your anion. Look at the positive amine, it's automatically going to be acidic.

This too, this could be an amine, but what's messing it up? The chlorine at the end, so it's a salt, so break it up. We know it has to be plus 1 because the halogens are in group 7a and they're -one. And look, we just isolated another positive amine, therefore it's acidic, just like this one is acidic. Finally, the last one. We could say that this portion here could be our amine. But what's messing it up? NO₂. Remember, NO₂ is our nitrite ion. All those polyatomic ions you guys had to learn earlier on, you still have to remember them. Here, this is going to be C₆H₅ NH₃⁺. This is going to be NO₂^-. Again, let's not worry about the negative ions just yet. What's important for right now is that we have a positive amine isolated, so it's going to be acidic.

So remember, if we have a transition metal, it needs to be plus 2 or higher to be acidic. If it's not, it's neutral. For main group metals, metals in groups 1a, 2a, 3a and 4a, they have to be plus 3 or higher or they're going to be neutral. And for the main group metals, if you really think about it, since the main group metals have to be plus 3 or higher, that automatically means that group 1a, which are plus 1, and group 2a, which are always plus 2, will always be neutral. So they're not going to meet the requirement.

So if you see a SALT question on your exam and it has a group 1a or 2a metal involved, automatically that metal is going to be neutral because it's not going to meet the minimum requirement. Group 3a is plus 3, so if you see aluminum or gallium or something, those will be acidic. It gets a little tricky in group 4a. If you have a periodic table near you, just take a look at it. In group 4a, we have Tin, Sn, and then we have Lead. Now, they're in group 4a. But remember, I said this several videos ago that these two, even though they're main group metals, they can act like transition metals. They can be either plus 2 or plus 4. So be careful, which one are they giving you? If they're giving you Sn²⁺ or Pb²⁺, their main group metals, they don't meet the minimum requirement of plus 3. So they would be neutral. But if you have Sn⁴⁺ or Pb⁴⁺, then they would meet the minimum requirements and they would be acidic. That one's a little tricky, so remember that.

Ionic Salts (Simplified) Concept 4

Now, finally, we've talked about the anions, well, the positive ions, I mean. Now, we're going to talk about the anions and negative ions. This one's a little bit trickier and it requires you guys to remember the rules that you learned in terms of what's a weak or strong acid. So, the rules that I taught you are still in play. So, here we're going to say, if you have a negative ion, then add an H+ to it. If you create an acid, then your negative ion is basic. So, let's take a look and figure out a good example of this. Let's say we have BrO₋ and we have Br⁻, 2 negative ions. So, to both of them, we're going to add an H+. Now remember, if you add an H+ to it, you're going to create an acid. You just have to ask yourself, what type of acid am I creating first? Remember, we said this earlier, there are 2 types of acids. There are binary acids which have no oxygen, and then there are oxyacids or oxoacids which do have oxygen. The first one HBrO has hydrogen, a non-metal, and oxygen. It's an oxyacid. All we have to do now is use the rules that we know. We take the number of oxygens, which is 1, and we subtract it by the number of hydrogens which is also 1. You need a minimum of 2 oxygens left to be strong. Here, you have nothing left, so we classify this oxyacid as a weak oxyacid. And we just said if you create a weak acid, then your negative ion will be basic. So since we have a weak oxyacid here, this negative ion is basic.

Now, let's look at the other one, HBr. HBr has hydrogen connected to an electronegative element Br, and it has no oxygen. This is a binary acid. And we said earlier that there are only 3 types of binary acids that are strong. The 3 strong binary acids are HCl, HBr, HI. Look, we have HBr here. So this would be a strong binary acid. Remember, we just said you have to create a weak acid so that your negative ion is basic. Here, we just created a strong acid. So that means that this negative ion would actually be neutral because it fails to meet the requirement. Basic ions are a little bit more difficult because we have to add an H+ to it and see what kind of acid we create. Because this all goes into the theory of, if you have a weak species, then its conjugate will be stronger than it. It won't be strong at the end of the day, but it'll be stronger than where it came from. So, because we start from a weak oxyacid here, that means that its conjugate base would be more basic, it would be a stronger base. That's why BrO⁻ is basic. Here, we have a strong acid, so that means that its conjugate base would be extremely weak. Because remember, whatever you are, your opposite is going to be very, very different from you. So because we have a strong binary acid, acid, strong acid means you create a weak base. Weak acid means you create a stronger base. The base will be stronger, it'll still be relatively weak compared to other strong bases, but it'll still be stronger than the acid it came from. So just keep applying this rule. Focus more on the anions because it's a little bit more difficult like I said. You have to add an H+ and follow the rules that we learned about when it comes to identifying acids and bases. As long as you can remember that, you'll be able to answer these types of questions.

Ionic Salts (Simplified) Example 1

Hey guys, in this new video, we're going to put to practice some of the concepts we learned about salts when it comes to acid-base neutralization. So let's take a look at this first example. We're going to say here, determine if each of the following compounds will create an acidic, basic, or neutral solution. So, we're going to have to break them up into their ions. We're going to take a look at the positive ion and see if it's acidic or neutral. And then we're going to take a look at the negative ion and see if it's basic or neutral. So for the first one, we're going to say it's NaOCl. Now remember, this is easy to break up. The metal always breaks off by itself. And, we know that Na is plus 1 because it's in group 1a. And then our negative ion would be OCl^-. Remember, if we take a look at the positive ion, Na is a main group metal. Main group metals have to be plus 3 or higher to be acidic. Because this is only plus 1, it fails to meet the requirement, so it's neutral. Now, let's take a look at the negative ion. Now for this negative ion, we're going to have to add an H⁺ to it, so we get HOCl. Every time you add an H to it, you're going to create an acid. This one has an oxygen in it, so we just created an oxyacid. Do the math. If you do 1 oxygen minus 1 hydrogen, you have nothing left. So this would be a weak oxyacid. And, remember, what does the rule say? It says if you create a weak acid, then your negative ion will be basic. And since we just created a weak oxyacid, that means that this negative ion is basic. So, we have a neutral ion, we have a basic ion. Neutral means we can ignore it. That means it doesn't affect the solution at all. So, we're going to look at the basic ion. The basic ion will make our solution basic. It's as simple as that. So, if you have a neutral and a basic, it gives you basic. If you have a neutral and acidic, it gives you acidic. If you have neutral and neutral, you're going to be neutral overall. And then, in some rare cases, we can have acidic and basic. We'll take a look at how exactly do we approach that later on down this page.

Ionic Salts (Simplified) Example 2

So, for the next one, we have PbCl₄. We have to break this up into its ions. Just realize here, you see this little 4? That came from the lead. So it's lead 4 positive plus chloride ion which is Cl^-. All you're going to say now is, this is a main group metal because it's in group 4a and it's plus 4. Main group metals have to be plus 3 or higher to be acidic. This one is definitely within the requirement, so it's going to be acidic. This Cl^-, add an H positive to it, you create an acid. Since it doesn't have any oxygens, it's a binary acid. And remember, HCl is one of the 3 strong binary acids. And we're going to say here, if you create a strong acid, then the negative ion has to be neutral because it goes against the rule that we talked about. So this here would be neutral, so we can ignore it. So we said earlier, if you have an acidic and a neutral, you're acidic overall. So, this is the approach you have to take with each of these. So, I want you to take a look at practice 1. For this one, you need to do the same thing. You need to break those 2 compounds into their ionic forms, then use the rules that we've gone over. Once you do that, you can figure out if they're acidic, basic or neutral. Good luck on this first one guys.

Determine if each of the following compounds will create an acidic, basic or neutral solution.

a) LiC₂H₃O₂   b) C₆H₅NH₃Br

• A. a) acidic b) basic
• B. a) acidic b) acidic
• C. a) basic b) acidic
• D. a) basic b) basic

Determine if each of the following compounds will create an acidic, basic or neutral solution.

a) Co(HSO₄)₂           b) Sr(HSO₃)₂

• A. a) acidic b) basic
• B. a) basic b) basic
• C. a) acidic b) acidic
• D. a) basic b) acidic

Here’s what students ask on this topic:

What are ionic salts and how are they formed?

Ionic salts are compounds formed from the neutralization reaction between an acid and a base. During this reaction, the hydrogen ion (H⁺) from the acid combines with the hydroxide ion (OH^-) from the base to form water (H₂O). The remaining ions, a cation (positive ion) from the base and an anion (negative ion) from the acid, combine to form the salt. For example, when hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH), the products are water and sodium chloride (NaCl), an ionic salt.

How do you determine if a salt is acidic, basic, or neutral?

The acidity, basicity, or neutrality of a salt depends on the properties of its constituent ions. For cations, transition metals with a charge of +2 or higher are acidic, while those with a charge less than +2 are neutral. Main group metals with a charge of +3 or higher are acidic, while those with a charge less than +3 are neutral. Positive amines are always acidic. For anions, add an H⁺ to the anion to form an acid. If the resulting acid is weak, the anion is basic; if the acid is strong, the anion is neutral.

What are the rules for determining the acidity of transition metal cations in salts?

Transition metal cations in salts are considered acidic if they have a charge of +2 or higher. For example, zinc (Zn²⁺) is acidic because it meets the +2 charge requirement. However, if the transition metal cation has a charge less than +2, it is neutral. For instance, silver (Ag⁺) is neutral because it does not meet the +2 charge requirement.

How do you determine the basicity of anions in salts?

To determine the basicity of anions in salts, add an H⁺ to the anion to form an acid. If the resulting acid is weak, the anion is basic. For example, adding H⁺ to BrO^- forms HBrO, a weak acid, indicating that BrO^- is basic. Conversely, if the resulting acid is strong, the anion is neutral. For instance, adding H⁺ to Br^- forms HBr, a strong acid, indicating that Br^- is neutral.

What are positive amines and how do they affect the acidity of salts?

Positive amines are compounds containing nitrogen and hydrogen or carbon, hydrogen, and nitrogen. In salts, positive amines are always acidic. For example, in NH₄Br, the NH₄⁺ (ammonium) ion is a positive amine and is acidic. Similarly, in CH₃NH₃Cl, the CH₃NH₃⁺ ion is a positive amine and is acidic. The presence of a positive amine in a salt ensures that the salt will have acidic properties.