00:01
Hello students, in this question one mole of toluene mixed with one gram of polystyrene.
00:06
These are the various values given in the question.
00:09
We have to find out the del h that is the enthalpy of mixing, entropy change of mixing and the free energy change of the mixing.
00:18
So, in order to find this first of all we want to know the mole fraction of the polystyrene.
00:25
So, for that we are going to find out the volume of the mixture.
00:31
So, this can be find out from the density formula.
00:34
Rearranging the density formula we will get volume is given by mass divided by the density.
00:40
Substituting the value the mass of polystyrene is one gram and the density of the mixture is 1 .05.
00:47
On solving this we will get the volume of the mixture will be equal to 0 .952 centimeter cube.
00:57
So, using this we are going to find out the mole fraction of the polystyrene and now we are going to calculate the number of moles of polystyrene which is given by mass divided by molar mass of the polystyrene.
01:13
Substituting the value mass of polystyrene is one gram divided by molar mass is 105.
01:19
On solving this we will get the number of moles will be equal to 0 .0095 moles.
01:27
Now, we are going to calculate the mass of the toluene.
01:31
The mass of the toluene can be calculated using the density formula which is given by density into volume of toluene.
01:40
Substituting the value the density of the toluene is 0 .8669 gram per centimeter cube into volume of the mixture which is equal to 0 .952.
01:56
On multiplying these two we will get the mass of the toluene will be equal to 0 .8253 gram.
02:05
Now, we are going to calculate the number of moles of toluene which is given by mass divided by molar mass 0 .8253 divided by molar mass of toluene is 92 .14 grams per mole.
02:18
On solving this we will get the number of moles will be equal to 0 .009 moles...