Hey guys in this new video, we're gonna do something incredibly important calculating equilibrium concentrations. Now, up to this point, I've been giving you questions in which our reaction is at equilibrium and the numbers I'm giving you are equilibrium amounts. Now, we're gonna be tasked with figuring out what those equilibrium amounts when I give you just initial concentrations. Now remember initial concentrations and equilibrium concentrations are totally different. And we're gonna say sometimes we'll be asked to calculate concentration of equilibrium. After being given initial concentrations, we're gonna say in order to do this, we're gonna have to use our favorite friend the ice chart and remember what does I stand for? I stands for initial change equilibrium. And we're gonna learn how to use an ice chart. And when do we use an ice chart? And what we should realize here is that ice charts are only allowed to have two types of units. We're gonna say they're used to having atmospheres or molar as the units. And remember why those two units because atmospheres are connected to K P and molar is connected to K C. We're still gonna be dealing with our equilibrium constants because they go hand in hand with our ice charts. Now, when do we use an ice chart? You only ask yourself one question or really you say one thing you're gonna say any time we have more than one compound in our balanced equation without an equilibrium concentration, then we have to use an ice chart. So before we start this next question, what do I mean by this? In the next question, we have three compounds within our balanced equation. Let's say I gave you the equilibrium amounts for two of them, we'd only be missing one person at equilibrium. In that case, we wouldn't need to do an ice chart. But let's say I gave you only one person at equilibrium. Technically, we'd have to do an ice chart in order to organize our work to see what the correct answer would be. So again, if you're missing more than one compound at equilibrium, you should use an ice chart. And if you don't have anyone at equilibrium, then you should definitely use an ice chart.