00:01
Hi, so to solve for this we will use the formula for osmotic pressure.
00:06
Osmotic pressure is equivalent to the van't hoff factor multiplied by the molarity of the solution or the ideal gas constant and t, the temperature.
00:14
Let's calculate first for the molarity of the solution, m.
00:19
This will be osmotic pressure over irt.
00:23
Osmotic pressure is said to be 4 .90 atm.
00:27
Van't hoff factor, this is not electrolyte, therefore this is just 1.
00:32
R is 0 .0821 liters atm per mole kelvin.
00:38
The temperature is 25 degrees celsius plus 273 .15.
00:43
We need to convert this to kelvin.
00:45
Now let's cancel some units.
00:47
We could cancel atm and kelvin.
00:50
The remaining units are moles per liter.
00:53
Sorry, let's use other color for this.
00:57
Moles per liter.
00:58
Those are the remaining units.
01:00
So molarity is therefore equivalent to 0 .200.
01:04
That's moles per liter.
01:07
Now we'll assign a variable to our unknown.
01:10
Let x as the molar mass of non -electrolyte.
01:28
So remember molarity is moles of solute over the volume of the solution...