[chocoholic4lyf]

which indicator will be sutable because i would have thought it to be methyl orange as it is a strong base and strong acid but some say that you should use Phenolphthalein

[Borek]

If you are titrating with strong base, phenolphthalein will do.

[chocoholic4lyf]

thanks

[sullivan_higgins]

Phew
i finally think i have enough down to write it up in class tomorrow
i think... 

it still doesnt feel like a solid investigation, but ah well. its what im writing.

[aliceGeez]

Hi,

I am also doing this AS Chemistry Plan, and am doing pretty much the same as the rest of you!

I am reacting Mg with H2SO4 for the gas collection, and H2SO4 with NaOH for the titration.

I was just wondering how you can prove the acid is dibasic using the stoichiometry.

Like n=cv n=m/M and n=v/Vm?

Any ideas??

Thanks

[merkl]

Oh, my gosh.

This has got so much bigger since I checked back - I'm kinda bummed that I posted all this up though, because it's giving everyone else who's read it an easy ride.

Anyway, updates: I got my work done, and changed my gas collection metal to magnesium, from Iron, as my teacher pointed out that Iron would react very slowly.

Back on the equivalent mass topic: I asked my teacher about that too, and she said it would be a much better way of doing it, and taking the second equivalence point of the sulfuric acid would be a much more sound method, but for the level of chemistry Im studying, the method I posted was pretty good. Flawed in places, but all in all good enough.


All I've really seen in this thread is rehashes of what I posted I think, but I hope what I posted helped some other people think up their own methodology.

All in all though, Im really glad of the help I got!

[merkl]

Also, on the topic of indicators:
Phenolphthalein of methyl orange (which were the two Ive learned about will work) - glad I looked that up as well.


The equivalence point of the strong acid/ strong base titration covers the pH range for both indicators.

Hope that helps out too.

[Borek]

The equivalence point of the strong acid/ strong base titration covers the pH range for both indicators.

May depend on the concentration.

How is it that all these plots are described as acid/base yet they start with high pH? A little bit misleading.

[merkl]

It did say on the site I got it from that the acid and base were of the same concentration, forgot to add that. Also, that is misleading, but it was the best I could find.

A friend asked my why he could use either indicator for his experiment, and it was the best way I could show him that the equivalence point would cover both indicators (again, depending on the concentration)

[Borek]

Check pH calculator link from my signature

[whoooosh]

How are we actualy meant to work out how much sulphuric acid we need for the titration ?

[chocoholic4lyf]

what type of titration would be best an acid-base titration or a neutralisation titration?

[Borek]

what type of titration would be best an acid-base titration or a neutralisation titration?

What's the difference?

[chocoholic4lyf]

oh i thought they were different, but obviously not!

[sErIoUsLy?]

then use this to work out the Mr
which should show you it is dibasic

This is probs gonna sound rly dumb bt I knw the Mr of H2SO4 is 98 . . . .bt how does this prove if its dibasic or not? 
And Im sooo confused about what to do for the gas collection method,  apparently we shld use Magnesium carbonate and sulphuric acid - producing magnesium sulphate, water and carbon dioxide bt how does this tell you whether its dibasic or not!?

I was off school recovering from surgery when the teacher explained it so Im now VERY confused lol.  If anyone has any advice it would be much appreciated!!  xxx