 Okay, so let's start with this equation here, this balanced equation, so it's already been balanced for you. So you know it's an equilibrium equation. Why? Because you got the equilibrium error there, okay? So if you were to ask to write the expression for the equilibrium constant, that just means to write what the equilibrium constant would be. Don't put numbers in or anything like that, so the expression, right? So k e q, remember, equals the concentration of products that are in gashes or aqueous form over the concentration of reactants, both raised to their coefficients, okay? So here on the product side, we've got one gas, ammonia, or NH3, and it's going to be raised to the second power there, okay? So it's going to be squared. And we're going to divide that by the molar concentration of nitrogen gas, and then multiply that by the concentration of hydrogen gas raised to the third power, okay? So that would be the equilibrium constant. If you were given numbers for these concentrations, you could actually put them into the equilibrium constant and solve it, and we'll do that in a second, okay? So if there are any questions about this one, we'll do one more of these. They're pretty straightforward, so we'll do one more.