The Student Room Group

Concentration halved then by X10? HELP

If a solution is diluted by halving the concentration and then dividing this halved solution by a factor of 10, what is the overall dilution?
Reply 1
Original post by garlicbreadman
If a solution is diluted by halving the concentration and then dividing this halved solution by a factor of 10, what is the overall dilution?


you are simply dividing the diluted solution into 10 portions, so all of them should have the same concentration from previous dilution. you see what i mean, that is if you dilute them properly, ie thoroughly shake the dilution mixture.
Reply 2
what do you mean dividing by a factor of 10? just like taking a tenth of the solution out and placing it in a beaker? In that case it won't affect the concentraition unless the beaker it's poured into is full of a solvent so you would've only just halved the concentration so the level of dilution shouldn't be affect by the dividing by 10. So the conentration is 1/2 of what it orignally was.

If you meant reduce the level of concentration by a factor of 10 then the overall dilution is such that the concentration has been reduced to be 1/20 of what it originally was.
(edited 13 years ago)
Reply 3
Concentration: Half

Amount in each division: A tenth
First, I put 25ml of the solution into a 50ml standard flask and made it up to the calibration mark with deionised water.

Then I took 10ml of this, placed it into a 100ml flask, and made it up to the calibration mark with deionised water.

Please don't say that the concentration doesn't change because I will commit suicide then!


Original post by Fat-Love


If you meant reduce the level of concentration by a factor of 10 then the overall dilution is such that the concentration has been reduced to be 1/20 of what it originally was.

:smile: So does it make sense to say the final solution is 5%, and that it the original has been diluted by a factor of 20?
(edited 13 years ago)
Reply 5
You have half the amount at 1/20th of the original concentration in that 100ml flask.

In response to your question, yes.
Original post by fibrebiz
You have half the amount at 1/20th of the original concentration in that 100ml flask.

In response to your question, yes.

cheers
Reply 7
God , it's just like
if you have 100ml of 100% and you add 10 ml that gives you 90%
it's the same if you have 50ml of 100% and now you add 5 to make it 90%

In otherwords, adding ten 50ml is the same as adding 20 to 100ml...and so on , am i right???
Original post by garlicbreadman
First, I put 25ml of the solution into a 50ml standard flask and made it up to the calibration mark with deionised water.

Then I took 10ml of this, placed it into a 100ml flask, and made it up to the calibration mark with deionised water.

Please don't say that the concentration doesn't change because I will commit suicide then!



:smile: So does it make sense to say the final solution is 5%, and that it the original has been diluted by a factor of 20?

Quick Reply

Latest