 Okay, so let's try one of these problems. Given that the Ka for HCN is 4.9 times 10 to the negative 10, and the Ka for water is 1.80 times 10 to the negative 16, will the following reaction occur? Please explain. So what is this asking us? It's asking us, well, will the products be favored at equilibrium? Okay, that's what it's really asking us. So in order to do that problem, we have to remember that the KEQ describes whether the products will be favored or the reactants will be favored, okay? So the KEQ of the reaction is unknown at this point. But if the KEQ is greater than 1, then the products are favored. But if the KEQ is less than 1, the reactants are favored, okay? So how do we determine the KEQ, do you remember that? Okay, so there's a formula you're going to have to remember. So KEQ equals the Ka of the reactant acid over the Ka of the product acid, okay? So it's not too difficult, but if you don't remember the equation, you're not going to get this problem. Correct, okay? So now we've got to identify, well, which one's the reactant acid and which one's the product acid, okay? So this is an acid-base reaction. We have to identify which one's the acid, which one's the base. Can we do that? Yes. What is this? Acid. Acid, this one? Base. Base, okay? So this is the acid, and is this the reactant side of the product? Reactant side. Okay, so this is the reactant acid, and which one's the acid, left or right? C. This one? Or this one? This one here? Why do you say that? What would be the conjugate? Okay, you can think of it that way, and a better way to think of it would be like, well, what do you have to have to be an acid? Hydrogen. Hydrogen. Does this thing have a hydrogen? So can it be an acid? No. Okay, so this is the what? The acid. Acid, and this is the product acid, right? Product. And if you were wondering, right, this problem was really nice. It gave us, so it told us what the acids were, okay? So you didn't even have to go through it. But it's good for you to do that, okay? Okay, so do we have the KA for the reactant acid? Yes. Do we have the KA for the product acid? Yes. Should we be able to do this problem? Yes. Okay, so let's just plug and check now, right? So 4.9 times 10 to the negative 10 divided by 1.80 times 10 to the negative 16. Remember to bring your calculator. Okay, you might expect this, and as you should, right, if you just look at these, you should expect KEQ to be bigger than 1 because the smaller exponents on the bottom, right? And specifically, it's going to be 2.7 times 10 to the 1, 2, 3, 4, 5, 6. So 2.7 times 10 to the 6. That's like 2.7 million or something like that, right? So is that bigger than 1? That is much bigger than 1, right? So is the product going to be favored? So will the reaction occur? Yes. Yes, the reaction will occur. Why? Because KEQ is greater than 1, okay? Any questions on this one? No questions.