 Okay. So let's try this one then. Calculate the osmotic pressure of 0.50 molar NACL at a 25 degree Celsius. So the first thing we have to do is figure out the osmolarity of this solution. So we've got to remember the chemical equation NACL we're assuming that the solvent is water in this problem. So from this equation we can calculate the molarity or the osmolarity of the solution. So we have a 1 to 1 to 1 ratio. So the ions dissolved relative to the reactants are 2 to 1 because 1 plus 1 equals 2. So we have a 2 to 1 ratio of the osmolarity to the molarity. So the osmolarity of the solution is going to equal 2 particles we could say to 1. So when we multiply this out we see that NACL cancels out there and we get 2 times 0.5 moles of ions. So that's going to be the osmolarity of the solution. So you could write it 1.00 molar or osmolar every one. 1.0. Huh? Only 1.0. Oh 1.0. Okay and now we'll use the equation for osmotic pressure which is this is the osmolarity and R. If you can write it osmotic. You think so? Yeah so you bet. So we'll do this. Let's plug in numbers. So that's the osmolarity. The temperature here is 25 degrees Celsius so we're going to have to convert that to Kelvin. So temperature equals 25 plus 273. And now we're going to erase this top part here. So if we just plug these values in. So osmotic pressure you want to get pressure units for that. So it's going to be an ATM actually. R is going to be the gas constant. That'll be given to you. 0.08 molarity. 1.0 ATM. So and the final answer for this is 2 sick figs. It's going to be 24 ATM. Osmotic pressure.