You are Here: Home

# titrations watch

1. In titrations (redox titrations), when we take a sample ((aliquot) like 25 cm3 of 250) of the original solution does the concentration change or remain the same???? Ik the moles change due to the change of volume only.. But yeah I'm not very sure Can someone explain whats going on
2. The concentration remains the same (theoretically).

The volume, as you know, changes but so does the mole value. Thus, when you divide these together, you'd virtually get the same concentration as the one from the original solution.
3. Its like having twenty apples and ten baskets. If i distribute them equally, each basket would have two apples. (just like concentration)

So if you pick a sample of, say, two baskets, you'd get four apples.

But the "concentration" is still the same as you still have two apples in each basket.
4. (Original post by MAS98)
The concentration remains the same (theoretically).

The volume, as you know, changes but so does the mole value. Thus, when you divide these together, you'd virtually get the same concentration as the one from the original solution.
yup so thats actually what I had understood till I saw this question
in q 21)iv) it says calculate the difference between the initial and final concentrations, aren't they the samee ugh

the q is from IAL 2015 June, I've attached it below
5. here is it
Attached Images

6. sorry forgot to attach part ii)
Attached Images

8. Hi sorry for the wait. Was a bit busy. But from my understanding it wants the difference between the conc of the solution used to SOAK the skin and R.

If you look at the paragraphs before the first question, I guess the initial concentration is the one given with 226.8g and 45dm3. So you have to essentially calculate the initial concentration (in mol/dm3) by using the Mr.

Then once you get that, you'd need to use the concentration of R that you calculated in the question before to find the difference.
9. To put it into perspective, if you're also asking why they're both different concentrations,

Initially, you had a fixed intitial concentration of KOH.

Then the solution was used to soak the animal skin, so some of the KOH took part in a reaction to form, say, A.

The remaining KOH particles (or the residue) is now inside a solution with A (sharing the total volume). So the concentration with respect to KOH decreases.

Well at least thats how i see it. Sorry my chemistry is a bit rusty as I graduated from A-Levels last year but i hope you understand! If you have any questions let me know I'll be glad to help.
10. Thanks sooo much!

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: May 28, 2016
Today on TSR

### The most controversial member on TSR?

Who do you think it is...

### Uni strikes! How do they affect you?

Discussions on TSR

• Latest
Poll
Discussions on TSR

• Latest

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE