# A #5*g# mass of polystyrene exerts an osmotic pressure of #1.21*kPa# at a temperature of #523*K#. What is the molecular mass of the polystyrene?

##### 1 Answer

#### Explanation:

And thus

Note the dimensional consistency. I changed the pressure into units of atmospheres, because this gives us a better idea of dimensionality. Of course,

And thus,

So, finally,

How many formula units of