00:01
Hello students, in this question the mass of the copper sulphide is given which is equal to 80 gm and the volume is given 1000 ml and now this has been diluted to 1 is to 10 ratio and then it has been re -diluted to 5 is to 25 ratio.
00:17
So we have to find out the mass of copper sulphide in 1 litre at the final stage and the molarity of the solution followed by normality of the solution and then we have to find out the weight to volume percentage.
00:35
So at first the solution is diluted to 1 is to 10 ratio that is 1 part of the original solution is added to 9 part of the solvent.
00:52
So the volume of the solution after first dilution will be equal to initial volume that is 1000 ml into 1 plus 9.
01:03
On solving this, this will be equal to 10000 ml and again it is re -diluted to 5 is to 25 ratio.
01:13
So on cancelling out this, this will be equivalent to 1 is to 4 ratio.
01:17
Then 1 part of the original solution is mixed with the 4 part of solvent.
01:27
So now we are going to calculate the volume of the solution after the second dilution.
01:35
So this will be our final volume which is given by before the stage volume 10000 ml into 1 plus 4.
01:46
This will be equal to 50000 ml.
01:50
So this is equal to on dividing by 1000 will be equal to 50 litre.
01:55
So now we are going to calculate the mass of copper sulphide at 1 litre in the final stage.
02:05
So this 50 litre would contain 80 gram of copper sulphide.
02:13
Then 1 litre of the solution would contain 80 divided by 50 gram of copper sulphide.
02:23
So on dividing this, we will get the mass of copper sulphide that would present in the final stage at 1 litre will be equal to 1 .6 gram.
02:34
Coming to the second part of the question, we have to find out the molarity of the solution which is given by number of moles divided by volume.
02:44
So at the final stage, the solution contain 80 gram of copper sulphide...