 All right, I'm going to go through the study guide. Hopefully you've done it, and you can check your work. And you can see how you did with it, figure out what you need to study before our test on Thursday. First question here is just understanding what side of the equation is what, being able to work with the terminology. We're talking about the starting substances. We're talking about the substances that are over here on the left side of our arrow. Those are our reactants. The products are over on the right side. So you start with reactants, you end with products. That's what that question is meant to review. Number two, an equation that does not indicate the ratio of reactants and products. That means it's a chemical equation. It's got all the symbols and formulas in it. There's no words in it, but it's not balanced. That is a skeleton equation. The skeleton equation is the one before we balance it. The arrow in a reaction means to produce. The arrow means to produce. Plus signs have different meanings. A plus sign on the reactant side, that means reacts with. And a plus sign on the product side means and. So when we're interpreting those chemical reactions, we're reading our way through them when we come to the arrow, we say to produce. Most of the time, if it's a decomposition reaction, we might say decomposes to produce just so we can have a verb in there. We come across a plus sign on the reactant side. We say reacts with. We come across a plus sign on the product side. We say and. AQ stands for aqueous, which means dissolved in water. Most of our ionic compounds don't react unless they've been dissolved in water. So you see aqueous quite a lot in a chemical reaction. S means solid. Remember, we look for those solids on the product side and precipitation reactions. You see an L, that means liquid. And a G means gas. The whole numbers that are put in formulas to balance an equation, we're talking about that too. In front of the H2O, that is a coefficient. The other two numbers are subscripts and superscripts. That is a subscript. And a subscript tells you the number of atoms. That too means we have two hydrogen atoms. And a superscript would be that number. Superscripts tell us charges. All right, reaction, we actually have to do something with it. What type of equation is this? What type of reaction with this? Well, I've got a plus sign on both sides. So that means it cannot be synthesis or decomposition. So it has to be single replacement, double replacement, or it's combustion. So to just figure out what it is, we have to look at what we've got. This has got three capital letters in it, that's a compound. That's got two capital letters in it, that's a compound. That's got two capital letters in it, that's a compound. That's got three capital letters in it, that's a compound. Everything's a compound that makes it double replacement. Now if we have a solubility table with us, we can go even further and determine if that's a precipitation reaction. To do that, we have to look at silver on our solubility table. Silver's right there. And we have to go down to the nitrate row, what it's been bonded with. So, silver's on the very edge of our screen here, that's silver. The nitrate row is here. It says soluble. So that means the silver nitrate is aqueous. Now the H2S. So we go on to our table here, which does not contain hydrogen, does it? Well, I can tell you H2S is soluble. So that one didn't work out quite the way I wanted it to, but hydrogen compounds tend to be soluble in water. Those are acids when they dissolve in water like that. Silver and sulfur. So, get this lined up. There's the silver. There's the sulfur. Insoluble, so that will be a solid. And that's another hydrogen compound, hydrogen and nitrate. Again, these hydrogen compounds, they are pretty soluble things. Again, they're acids. So we have two aqueous making a solid. This would be precipitation reaction. The ones that you'll have to do for me on the test will be on the table, so you don't have to worry too much about that hydrogen thing. Let's balance this equation. I'll copy it down here. On the reactant side, we have one silver. Now we come to the nitrate, the NO3, and we have to decide if that's something that we can keep whole or not. Again, if we can have it on both sides of the equation and the elements in it aren't found anywhere else, this contains no nitrogen or oxygen. That contains no nitrogen or oxygen. We don't have to break it down. So we can say we have one nitrate over here. And the reason why we say we only have one is because there's no parentheses around it. If there were parentheses around it, we'd go with the number on the outside. Hydrogens, I've got two. Sulfur, I've got one. Same list on this side. Sulfur, I've got two. Nitrate, I've got one. Again, there's no parentheses around it. Hydrogen, I've got one. Sulfur, I've got one. So I'm gonna start balancing this equation with my silver. Might as well go down the list. One on this side, two on that side. So let's take a two here in front of my silver nitrate. That gives me the two silvers I need to balance that out. But it will also double the number of nitrates that I have. So now there would be two on the reactant side. So I'll come over here to the product side and try to fix that, two and one. I'll put a two out in front of the hydrogen nitrate or again, it's an acid, really. Two hydrogens now and two nitrates. And my sulfurs are balanced. So my lists are the same. Two, two, two, two, two, two, one, one. So that is a balanced equation at this point. We'll be balancing this one as well. And I'll rewrite it so I give myself some room for my coefficients. And again, I'll start by breaking everything down. One iron, three chlorines, one sodium. Now I come to the hydroxide, the OH. Again, if I have it on both sides, like I do, and there's no oxygen or hydrogen here, there's no oxygen or hydrogen there, I don't have to break it down. There's no parentheses around the hydroxide, so there's only one. I make the same list over here. One iron, one chlorine, one sodium. And this time I have three hydroxides. I want to have parentheses. I go with the number on the outside. I make my list in the same order because my eye wants to go in a straight line. So I want to make sure that it can when I'm analyzing this. If I put iron here and then iron down there, my eye doesn't want to do that. My eye wants to go straight across and sometimes it'll see something that's not there. So we want to make sure we don't fool ourselves. So the chlorine's out of balance here. We can go ahead and start with that. We stick a three out in front of the sodium chloride to fix that. That will give us three sodiums, three times one. And three chlorines, three times one. Now I've just thrown the sodium out of balance. I got three on the product side. I have one on my reactant side, so I'll throw a three out in front of the sodium hydroxide. Three times one is three. Three times one is three. So that fix both things. And again, when these lists are the same, it's balanced. One, one, three, three, three, three, three. Everything's good to go. It asks which product in number seven is likely to be a precipitate. That's where we go back to our solubility table again, and we're looking for the thing that's going to be a solid. So I've got iron and I've got hydroxide. So I come to my table, there's iron. I've got to go to the hydroxide row, which is right there. Iron and hydroxide is insoluble, so that's it. That's the substance that's likely to be my precipitate, the one that ends up being insoluble on our solubility table, as we know salt dissolves in water. So that would be a quiz. Moving on. Question number nine. What type of reaction involves two or more substance forming a single new compound? Two or more substances forming a single compound, those two things joined together, that is synthesis. Single new substance means there's no plus sign on the product side. That's the key giveaway for synthesis reactions. A chemical change in which one element replaces another element in a compound. So we have one element replacing another element in a compound, a single replacement. Also called single displacement. So if you see displacement, it means the same thing. A table that lists your metals in order of decreasing activity, that table right there, there's our metals from the most reactive to the least reactive, that is called an activity series. Number 12, in order for a metal to replace another metal in a reaction, the metal must be what? On the chart. And again, so what we learned, when we're trying to figure out if replacement will happen, we have to look to see which one's most reactive. And the way it has to be is that your more reactive metal has to be free. Your less reactive metal has to be in the compound for the reaction to occur. So if in order for a metal to replace another in a reaction, the metal must be higher on the chart. The higher ones are more reactive. So that free metal has to be the more reactive one. That free metal has to be the one that's higher on the chart. What type of reaction is this? Well, that's decomposition. The reason I know it's decomposition is there's only one reactant there. The only type of reaction that has a single reactant is a decomposition reaction. Now we gotta write the products. And when we do the products in these decomposition reactions, all we're doing is breaking them down into the two elements. Li would be just Li, nothing special about that. But chlorine is one of our diatomics. The diatomics are hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine. They all have to have a subscript two on them. The diatomic elements, when they are by themselves, when they are an element, have to have that subscript two on them. On to page two. The starting substances, and that's the same page we already did. I'm doing that twice. Let's turn our sword at these. There we go. Page two. How many products are there in a synthesis reaction? One. Again, two elements will combine to make a single compound. Just one product in a synthesis reaction. The products in combustion are always carbon dioxide and water. One of the easiest ones to predict. Remember, a combustion reaction will have some kind of hydrocarbons, see something H something plus oxygen. And when you're asked to predict an equation like that, you just write down carbon dioxide and water and you're done. They're one of the easy ones to do. Number 16, will these proceed? That's a matter of figuring out which metals more reactive. So in our first one, my metals are lithium and magnesium. So let's look at the activity series and figure out where each one is. There's lithium higher on the list. It's at the top. And there's magnesium a good way down, almost halfway down. That tells us that this is the more reactive one. This is the less reactive one. And for a reaction to proceed, the more reactive one has to be free. So this one will proceed. So we have to replace those metals out. So magnesium will be the free metal now. And to figure out our compound here, our lithium chlorine compound, we have to use the crisscross method. Lithium's a plus one. It's in group number one. Chlorine is a negative one. It's in group 17. So we end up swapping out a couple ones here. And it ends up being L-I-C-L. Don't forget to crisscross when you're writing these formulas. So you look at our next one. Calcium and iron. So we have to get our activity series out again and find calcium and iron. There's calcium. There's iron. Calcium is higher than iron. So calcium is more reactive. And iron is less reactive. And again, for our reaction to proceed, the more reactive one has to be free, like it is. So the calcium will replace the iron. So iron will be the free element. And for our calcium and oxygen formula, we have to do crisscross. Calcium's a plus two. It's in group two. Oxygen's over in group 16. So it's a negative two. We're swapping out a couple twos, which in the end reduced to ones. So it's just C-A-O. Remember the plus two and the minus two basically just cancel each other out. So you only need one atom of each element to make that compound. Finally, nickel and barium. So let's look at our list. There's nickel. There's barium. So barium is higher. It's the more reactive one. Nickel is the less. And again, for this reaction to proceed, the more reactive one has to be the free element. This will not proceed. There will be no reaction. So MP for not proceed or NR for no reaction, whatever you want to do. That one will not react. All right, moving on. Those two, that is synthesis. The reason I know this is synthesis is because both of those are elements. Both of those have just one capital letter in it. For my products, I have to do the crisscross method. Aluminum is in group 13, so it's a plus three. Nitrogen is in group 15. So it's a negative three. Positive three, negative three cancel out. So we'd only have one of each. Or you can go ahead and cross a three and a three. Those can be reduced to ones. A-L-N is the formula. Don't forget the crisscross. I mean, that one worked out with no subscripts. That one worked out with no scopes. That one worked out with no subscripts, but that's not always the way it goes. So you gotta be careful. Make sure you check it. Next one up, type of reaction is this. It's a single replacement. I know it's single replacement. No, it's actually double. I thought that was an L. Or is it? Yeah, that's an L. This is an L in this formula here. Kind of look like an I for a second there. But that is an L. C-L2 and sodium iodide, chlorine and sodium iodide. Element compound, single replacement. Now our rule in single replacement is that like replaces like. So since chlorine is a non-metal, it has to replace the non-metal. So it doesn't replace the sodium, it replaces the iodine in this. So iodine becomes the free element. And it's one of those diatomics, so it has to have the two on it. And then for our formula, we have to crisscross. Sodium's a plus one, chlorine's a minus one. I really wish the person that wrote this didn't make it so simple. But again, there's no subscripts in that. This is just a review sheet I found on the internet and modified. Again, you've gotta do that crisscross. It's not automatically gonna be just one atom of each. Sometimes you have subscripts in there. So if this had been calcium instead, we'd have been moving a two over here to the chlorine. So do be careful. Make sure that you're doing that crisscross, making sure that you know what the subscripts are supposed to be there. And finally, 20 minutes into it. That's not too bad for a review sheet. If you know what you're doing, we gotta complete this reaction. That right there, the carbon dioxide and water tells that this is combustion. And the other reactant in a combustion reaction is oxygen. Well, I hope that was as much fun for you as it was for me. And maybe more than five or six people will watch it. And it'll be worth the time. Good luck.