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# AQA AS Chemistry ISA (Titration) watch

1. Titration

Right, the ISA tomorrow is a titration. My class have done a practice of it months ago to prepare for the real thing, but I only joined them for chemistry later, so I wasn't there for the practice.

I've read about titration and know what it is all about, however, as I haven't done it, I have a couple of things unclear about it:

(1) Reading the burette: I'll get marked for this, so I need to get it right... when I read the burette, do I read the level to which the acid has dropped e.g. from 50 cm3 to 45 cm3, and say "forty-five centimeters cubed", or do I calculate the actual volume used i.e. 5 cm3 in my head and say "five centimeters cubed"?

(2) The unit of the titration: I've seen this as a ratio in some places e.g. 1:2; is that the volume ratio? Or is the titration the volume of the acid e.g. 10 cm3?

I'm so confused right now.

> 25 rep points up for grabs if you need motivation
2. Please someone, I know this isn't as exciting as a model's hairy legs or someone's pubic hair, but I need it now!

3. A burette is usually from 0 isn't it. You'd just read the number it stopped at. Like if it stopped at 10 then it would be 10cm3 or whatever

Never heard bwt a ratio for titration (maybe I'm dumb), don't you just use the value from your titrations in all those moles calculations later :s

Sorry if it wasn't so helpful.
4. I do OCR, but I did a titration for my coursework as well.
How exactly are you being marked for it? Because we just had to shove our results in a table and were marked on that; if you're being marked similarly, then you'll be fine if you put the start reading, the end reading, and then the difference (the volume of the titre).
I would've thought it'd be the volume of the acid.
Although if the format of the AQA one is different, then just ignore that.
5. (Original post by Flying Cookie)
Titration

Right, the ISA tomorrow is a titration. My class have done a practice of it months ago to prepare for the real thing, but I only joined them for chemistry later, so I wasn't there for the practice.

I've read about titration and know what it is all about, however, as I haven't done it, I have a couple of things unclear about it:

(1) Reading the burette: I'll get marked for this, so I need to get it right... when I read the burette, do I read the level to which the acid has dropped e.g. from 50 cm3 to 45 cm3, and say "forty-five centimeters cubed", or do I calculate the actual volume used i.e. 5 cm3 in my head and say "five centimeters cubed"?

(2) The unit of the titration: I've seen this as a ratio in some places e.g. 1:2; is that the volume ratio? Or is the titration the volume of the acid e.g. 10 cm3?

I'm so confused right now.

> 25 rep points up for grabs if you need motivation
You draw calculate of level used, and initial reading, substract one from another: Initial-Final and label the result titre. It helps putting the data into a table.
You use volume units: cm^3, I think ratio refers to stocihiometric ratios in the reaction schemes, for instance 2moles acid used to neutralise 1 mole of base
7. (Original post by Flying Cookie)
Titration

Right, the ISA tomorrow is a titration. My class have done a practice of it months ago to prepare for the real thing, but I only joined them for chemistry later, so I wasn't there for the practice.

I've read about titration and know what it is all about, however, as I haven't done it, I have a couple of things unclear about it:

(1) Reading the burette: I'll get marked for this, so I need to get it right... when I read the burette, do I read the level to which the acid has dropped e.g. from 50 cm3 to 45 cm3, and say "forty-five centimeters cubed", or do I calculate the actual volume used i.e. 5 cm3 in my head and say "five centimeters cubed"?

(2) The unit of the titration: I've seen this as a ratio in some places e.g. 1:2; is that the volume ratio? Or is the titration the volume of the acid e.g. 10 cm3?

I'm so confused right now.

> 25 rep points up for grabs if you need motivation

The burette will start from 0 at the top and so you will start at a certain point above 0 (e.g. 8.5) and then slowly start releasing the substance. After you have finished, you will read the bottom of the meniscus to see your final value.
On your table, you normally have 3 rows which will include "Initial volume","Final volume" and "Volume used [Titre]". This is where you include all your data, and you may also have a "Mean Titre" row where you find the average of the differences in volume.

Hope this helps
8. The ratio may be the number of moles. You'll be able to work out how many moles of what's in the burette you've used, and can relate this to what you're titrating into.

H2SO4 + 2NaOH --> 2H2O + Na2SO4 so your ratio is 1 acid : 2 base, if you use 25cm3 0.1M H2SO4 then you have 0.0025 moles acid, and you know there's 0.005 moles of base in your sample.
9. Thank you everyone, I've had the practical assessment today, and I must say it was loads of fun I have the written paper on Friday, and hopefully I'll do well. I think I've now understood pretty much everything about titrations.

Thanks
10. Hello there, i have my ISA A (OCR - AS) tomorrow and it is also on titrations... does anyone know what sort of questions could come up / be asked??
11. Last year the written paper was mostly about calculations.
Revise percentage error as that 99% sure will come up!
Btw, this is AQA, but they must be similar.
Good luck
12. (Original post by FutureMedic)
Hello there, i have my ISA A (OCR - AS) tomorrow and it is also on titrations... does anyone know what sort of questions could come up / be asked??
Sure.

Add me on MSN (link somewhere top right of my post) and I'll send you the past paper and mark scheme.
13. Good Luck with ISHA.
14. Can i just ask.. are all the questions to do with calculating unknowns in the titration for example finding the conc of the other solution given one conc etc??

Thanks!
15. (Original post by Flying Cookie)
Sure.

Add me on MSN (link somewhere top right of my post) and I'll send you the past paper and mark scheme.
Flying Cookie, have you done the paper yet, If so what is there to revise? x
16. Hello,

I have my exam on Tuesday, and it will be really helpful if any one could tell me if any question like "suggest" and "why" come up, and if so what specifically come up.

p.s someone say something about relating to the industry what do they mean,

Once again thank you in advance.
17. Got this next week (aqa). If anyone wants to help me that would be nice
Got this tomorrow

Posted from TSR Mobile
Good luck! let me know how it goes and what turns up.
19. could anyone tell me what calcultaions involve in the paper im really struggling and would need practise at certain calculationes pleasee
20. Has anyone done the AQA ISA Chem paper yet? If so reply please

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