Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: merkl on March 21, 2008, 09:39:31 AM
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DELETED:
Answered: and I'd rather not have everyone copying my work.
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Logical approach is to determine its molar mass and equivalent mass.
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Ive had a quick read up on that,
Molar mass of the acid is 98, and i understand the equivalent mass is half that, but Im lost as to how I go about using that information.
I wonder whether Im supposed to know this method: Ive never been taught it.
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Your first post is pretty close, consider, you use the iron reaction to determine how many sulfates the "unknown" molecule has, then you use the titration reaction to find out, "Hmm...molecule can neutralize twice as much NaOH compared to how many sulfates it has" and you're done.
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All the time your problem is the same - you are trying to do two identical experiments, so they will not give any dirrent information. Neutralization reaction tells you how many H+ are in sample. H2 tells you how many H+ are in sample. This leads nowhere.
You have to find molar mass of the acid, and mass per one H+ (called equivalent mass). Divide first by the second and you will know number of protons.
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You raise a good point..my methods in no way prove the acid is dibasic. I missed the point completely.
I understand what you mean by the equivalent mass now, but Im not sure how I could incorporate into a titration/ gas given off experiment as my proof - at the moment it feels like the equivalent mass calculation would be my final proof, but again, I dont know how to come to that conclusion.
I'll continue reading up on it also and try and come up with a method, but any guidance is appreciated.
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Is the limitation (titration/gas collecting) yours, or is it forced upon you? Is it an experiment you are going to make, or the one you have to describe only? And finally - what data do you have as input (ie what do you "know" about sulfuric acid before experiments).
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It is a set experiment that we have to plan and describe, not actually perform. One method must include titration, the other a gas collection.
We are given the molarity of the acid as being 1.00moldm-3
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We are given the molarity of the acid as being 1.00moldm-3
Well. if you KNOW that solution IS 1 mole per liter, you have to determine number of equivalents in this solution - and this will be answer to your question.
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And I can do this using both a titration and gas collection? If so, i'll get to thinking about it, and post back when i get somewhere, ( or not, if that so happens to be the case).
EDIT: would it be possible for you to explain the idea of an equivalent, perhaps in a reaction: i've looked it up on wikipedia, and the article doesnt offer me much that I can understand.
Thanks so far!
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This may be a silly question but could you use a potentiometric titration?
just a thought :)
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Assuming you mean it dissociates into two H+ ions...
-Do a neutralisation titration (using methyl orange or an equivalent as an indicator) of an equal amount (eg: 25ml) of 1M HNO3; 1M HCl and 1M H2SO4 (separately of course), using 1M NaOH.
-Record the volumes of NaOH needed to neutralise each.
-As they are strong acids the monoprotic acids (hydrochloric and nitric) should be within a reasonable margin for error (5%-ish), but roughly the same, showing that they have an equal proportion of H+ ions to be neutralised.
H+ + OH- > H2O
-However the diprotic sulphuric acid (yes I'm English) should react with twice as much NaOH, showing it has twice as many H+ ions.
2H+ + 2OH- > 2H2O
(^needs twice as many OH ions see)
So yeah pretty much what you said, except proving that two monoprotic acids will be the same.
Not sure about the gas, maybe: Metal + Acid > Hydrogen + Salt , but can't think of a great way of doing it off the top of my head. Well, good luck.
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Hey, im English too :P Didnt know diprotic was actually our way of saying it, but it makes sense.
I like your method though, I understand it fully. I want to see where this equivalent mass idea goes though. It sounds good.
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hey, im doing the same thing and im not sure either.
but i think for the titration u wld jsut do a regular titration, and then prove it is dibasic by simply working out the stoichiometry os the equation using your titration results.
and for the gas collection, clsdnt u simply react it with, say, iron, and collect the gas using a regular gas collecting method, and then simply work out the moles of hydrogen using the volume of hydrogen given off. but even though im sure im on the right trakck with this one, im not sure how to go about proving it's dibasic from here. wld u work out the number of moles of hydrogen that wld be present for that volume of sulphuric acid if it wasn't dibasic, and then work out the actual number of moles? :-\
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Read my 4th post I think and take a look at my proposed method.
If my idea for both the titration and the gas collection works (and I hope to god it does, because I spent three hours writing it up!) then you also are on the right lines with it.
Granted, it all feels a little bit vague and nothing is quite so conclusive as I'd like - Im still interested in Borek's idea of using equivalent masses, but I', still unsure about how I'd use it.
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I'm doing the same thing as you. For the gas collection, I've been thinking of doing an electrolysis in which hydrogen would be collected at the cathode (+ve ions gain electrons). Can't see how it would prove it though :/
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Electrolysis won't work - you will electrolyse water, not H+ from the acid.
As for equivalents.
Imagine you have a sample of acid of known mass.
Equivalent is formally defined as amount of substance that reacts with 1 mole of electrons. This definition is a little bit to narrow IMHO. Druing neutralization there are no electrons involved (well, they are, but it is hardly reaction WITH electrons). But - if you will react H+ with Zn - you will see that exactly 1 mole of H+ reacts with 1 mole of electrons. In the case of acids 1 equivalent is 1 acidic proton.
When you titrate it with base, you know how many acid equivalents have been neutralized. You don't know how many moles of acid it was. This gives you information about mass of equivalent, not about molar mass.
There are other methods of determining molar mass - freezing point depression, boiling point depression, volume of gas (PV=nRT) to name a few. Unfortunately, they are not easy to use in the case of sulfuric acid, but we are talking about general approach.
So, what you can do is to determine mass of equivalent by titration, then molar mass by other means. If they are identical - you know there is one acidic proton per molecule. If they differ - molar mass should be a multiply of equivalent, molar/equivalent mass ratio gives you number of protons.
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That equivalent method seems so much more definite. When I get back to school, I'll ask my teachers advice on it *as I dont know if we are expected to use that method or not*, then post back.
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hi eragon 11
i appear to be doing the same thing ...
im not sure what to do for the titration so if you could possibly repeat it in layman's terms.
However, in terms of the gas collection i was going to react both a monoprotic and a diprotic acid with magnesium carbonate MGCO3, recording the amount of CO2 given off, as the diprotic h2so4 would give off twice as much CO2
Am i going horribly wrong?
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can someone run through the method and calculations for the titration and gas collection experiment please? i have no idea and need help !!!
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ever tried titrating it and looking at the pH curve? it should have 2 equivalence points
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ever tried titrating it and looking at the pH curve? it should have 2 equivalence points
Not necesarilly. See plot.
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However, in terms of the gas collection i was going to react both a monoprotic and a diprotic acid with magnesium carbonate MGCO3, recording the amount of CO2 given off, as the diprotic h2so4 would give off twice as much CO2
Am i going horribly wrong?
Err yes, dibasic is how many h+ ions released. Keep it simply Do: Metal + Acid -> Salt + Hydrogen. a dibasic acid will produce twice as much h2 as a monobasic
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However, in terms of the gas collection i was going to react both a monoprotic and a diprotic acid with magnesium carbonate MGCO3, recording the amount of CO2 given off, as the diprotic h2so4 would give off twice as much CO2
Am i going horribly wrong?
Err yes, dibasic is how many h+ ions released. Keep it simply Do: Metal + Acid -> Salt + Hydrogen. a dibasic acid will produce twice as much h2 as a monobasic
Willowe asks about CO2, you answer about H2. Sometimes it helps to read the question before answering ;)
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I see a few british people have had their AS chemistry plans through...
Ahh, refreshing. So glad Ive done it now.
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so your second method, involving calculating how much base is needed to neutralise HCL and sulphuric acid before comparing the amount needed is the right way to go? that kind of makes sense to me but am quite unsure about the calculations invloved afterwards.
the gas collection...that just needs an acid and a metal reacting, and then the amount of gas collected and moles calculated blah blah?
sorry i'm a bit simple, and ive left all this way too late.
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Hey just got the plans for the planning stage of my AS chemistry coursework and i was just wondering if anyone could suggest a suitable indicator for use in the titration against NaOH, and also the colour change that you should expect to see.
Also in the gas collection, are you simply comaparing the amount of gas collected for a monoprotic and diprotic acid (obviously the diprotic will release twice as much) but im unsure of any calculations that could be done afterwards. I was thinking about weighing the metal before the reaction and working out how many mols of gas will be realeased for one mole on monoprotic and one mole of diprotic acid, but that essentially just shows what your experiment showed and so there doesn't seem much point
Also for the titration, my understanding is that it is used for finding concentrations of unknown soloutions, but since you should know the concentration of both soloutions (which i assume should be the same) how can calculations show sulphuric acid is diprotic??
Wow thats a mouthful, but if someone could give me some hints on that i would be really grateful!!
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For the gas collection, how would you go about proving how much sulphuric acid you need and how much metal (in my case iron) you need? the metal needs to be in excess, but how do i know how much that is? any help is greatly appreciated.
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Hey Eragon Cud U Pls Explain The Format Of Dis Plannin 2 Me
Cos I Dnt Undastand It & Cud U Pls Tel Me Which Acid Acts As d Standard Solution?
Fanxs
Please read forum rules (http://www.chemicalforums.com/index.php?page=forumrules).
English is official language here.
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is this for the chemistry plan? I'm totally lost as well... I don't know where to start really.
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Err yes, dibasic is how many h+ ions released. Keep it simply Do: Metal + Acid -> Salt + Hydrogen. a dibasic acid will produce twice as much h2 as a monobasic
but how would you actually measure the amount of gas? what apparatus would you need?
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http://www.practicalchemistry.org/standard-techniques/generating-collecting-and-testing-gases,52,AR.html
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hey, im doing the same thing for my exercise.
ive got the titration done easily as well as all the calculations for it, same with the gas exchange, but the problem i am having is proving it is dibasic with a gas exchange, i know i have to react MgCO3 with HCl and H2SO4 and im fine with the H2SO4 bit. but why HCl, and what is the reaction?
i know it should take double the amount of HCl to neutralise but, why? or is this going to far, and to indepth.
anyone want to help me out.
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how should i decide on the volumes or quatities of reactants to use, and how can i use calculations to prove why i chose them?!
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hunibunch - calculations and reactants and masses for which experient?
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hey, im doing the same thing for my exercise.
ive got the titration done easily as well as all the calculations for it, same with the gas exchange, but the problem i am having is proving it is dibasic with a gas exchange, i know i have to react MgCO3 with HCl and H2SO4 and im fine with the H2SO4 bit. but why HCl, and what is the reaction?
i know it should take double the amount of HCl to neutralise but, why? or is this going to far, and to indepth.
anyone want to help me out.
dont make it too complicated use Mg instead of MgCO3
the equations will be as follows:
2HCl + Mg = MgCl2 + H2
H2SO4 + Mg = MgSO4 + H2
what you should find is H2SO4 releases twice as much gas as HCl
For calculations just work out values for one mole of each acid and prove H2SO4 is double.
You use HCl because HCl is a monobasic acid (it gives off one H+ ion) and you can compare it to a dibasic acid to show the difference between the two
hope that makes sense
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I've got this as my chemistry AS plan as well ;) I know what I'm doing for the titration and the only thing I'm confused about is why the metal needs to be in excess for the gas collection experiment? ??? I thought the acid would have to be in excess so all the metal reacted and the most hydrogen was produced ???
Can anyone explain this for me please?
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I've got this as my chemistry AS plan as well ;) I know what I'm doing for the titration and the only thing I'm confused about is why the metal needs to be in excess for the gas collection experiment? ??? I thought the acid would have to be in excess so all the metal reacted and the most hydrogen was produced ???
Can anyone explain this for me please?
Which reactant is in question? And which product will you be quantifying, and why? Try to figure it out again, along those lines, and see if it becomes clearer.
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I've got this as my chemistry AS plan as well ;) I know what I'm doing for the titration and the only thing I'm confused about is why the metal needs to be in excess for the gas collection experiment? ??? I thought the acid would have to be in excess so all the metal reacted and the most hydrogen was produced ???
Can anyone explain this for me please?
you need all the acid to react so you can compare the amount of gas given off for each acid, if it was the other way round you would find out gas given off for a certain amount of metal, or at least that is my understanding
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for the gas collection, do you have to use two different acids?
Couldn't you just use one acid (sulphuric) and then just use mole calculations to work out the number of moles and everything? Or do you have to use two different to compare them?
thanks
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hey, these replies help with the gas collection but not so much the titration... what exactly do you do for the titration?
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Can I ask the more recent posters in this thread, to please read the original question, and the earlier responses, and then, maybe, consider asking their own new question, as a new topic, if it's very different from the original?
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Yeah, I have read the more recent posts. And my question is very relevant to the actual coursework, but I really don't think you need to compare two different acids, I think it's just creating extra work for yourself.
I've got another question as well, you need the metal to be in excess yeah? but how do you work out how much will be excess? I don't understand.
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Am I right in thinking that sulphuric acid requires double the amount of NaOH or is it half, compared to HCl?
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Am I right in thinking that sulphuric acid requires double the amount of NaOH or is it half, compared to HCl?
Hello mate, i believe that the H2SO4 will produce double the amount of H2, than the HCL.
So, in effect to produce the same amount of H2, double the amount of HCL should be used.
Now for my own questions.
Now I think I know what to do for the gas collecting experiment, however I'm still having a few problems with the titration.
The whole point in titrations was to produce the concentration of the liquids used, to the best of my knowledge.
The only useful thing titrations would do in this context would be:
-This is a guess-
That double the amount of HCL would be needed as H2SO4 to neutralise the NAOH (maybe? - Please verify this chemical for this technqiue) as the HCL would need.
Now my problem comes when I think to myself:
In both my reactions, I am comparing two different chemicals, is it not possible to proove the H2SO4 is dibasic by just using calculations - especially in the titration.
Any help would be appreciated.
Thanks.
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you need all the acid to react so you can compare the amount of gas given off for each acid, if it was the other way round you would find out gas given off for a certain amount of metal, or at least that is my understanding
Thank you, I understand now :)
Just one more question; in the titration would you place the H2SO4 or the base (NaOH) in the burette because I was always taught to place the substance you know the most about in the burette but I know the same amount about both substances so I don't know which substance to put where? Can anyone help?
Thanks :)
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thanks for the gas stuff guys
the titrations is simpler, or atleast in my opinion. i used this equation:
2NaOH(aq) + H2SO4(aq) -----> 2H2O(l) + Na2SO4(aq)
using 10ml of the sodium hydroxide should mean that 5ml of sulphuric acid therefore it is dibasic as half the amount can neutralise and it produces 2h2o's to 1 h2so4.
you can also do (concetration of sodium * volume of sodium)/ (moles of sodium) = (concentration of sulhuric *vol of sulphuric)/ (moles)
(1*10)/2 = (1*5)/1
5 = 5
therefore this proves it is dibasic
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you need all the acid to react so you can compare the amount of gas given off for each acid, if it was the other way round you would find out gas given off for a certain amount of metal, or at least that is my understanding
Thank you, I understand now :)
Just one more question; in the titration would you place the H2SO4 or the base (NaOH) in the burette because I was always taught to place the substance you know the most about in the burette but I know the same amount about both substances so I don't know which substance to put where? Can anyone help?
Thanks :)
put the acid in the conical flask and the base in the burette this is what i found most effective as you need to wait for a colour change in the acid and it is easier to do it this way round as phenolphyalene (sorry if its spelt incorrectly) indicator turns from colourless to pink/purple which is a more obvious change than from pink/purple to colourless and so the results will be more accurate
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phenolphthalein
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I have this problem for my coursework too. I know that by doing the titration you will find out that it takes half the amount of H2SO4 to neutralise the NaOH and this can be shown by the equation because the ratio of moles of acid to base is 1:2 but how do you show that this proves that H2SO4 is dibasic?
Any help is greatly appreciated :)
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i am using this for the gas collection :
2HCl + Na2CO3 -> CO2 + H20 + Na2Cl
H2SO4 + Na2CO3 -> CO2 + H2O + Na2SO4
can anyone help me because i do not know how much of each thing to use???
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Can anyone help with the dilution quantities? im guessing that to dilute H2S04 of 1.00 mol, you would transfer 25cm into a 250cm volumetric flask and then fill the rest with water which would then give you 0.1 mol?
Another question is - why do we have to dilute the acid? Also, do we have to dilute both the acid and the base?
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Because reaching high up to pour 1M of NaOH or H2SO4 into a burette isn't the most sensible thing you could do.
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I'm sure that anyone who doesn't do AS OCR chemistry is pretty confused as to what we are exactly supposed to do
so here's the question
"Sulphuric acid, H2SO4, is a dibasic (diprotic) acid. This means that one mole of sulphuric acid can release two moles of hydrogen ions, H+, when it reacts in aqueous solution.
Your are required to plan two different experiments that would enable you to prove that sulphuric acid is dibasic.
One of your experiments should involve a titration and the other should involve collection of a gas.
Your planning must be based on the assumption that your are provided with the following:
- aqueous sulphuric acid, of concentration 1.00mol dm-3
- any chemicals (other than sulhpuric acid) and equipment that you require from your school/college laboratory. "
It then goes on to say that you should draw diagrams, etc.
It then says you need to show a specimen calculation to show how the basicity of sulphuric acid would be worked out from the titration data. Could anyone describe how to do this? I have no idea what basicity means.
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I know theres been quite a bit of help on the concentrations you need, but I just thought I'd point out that it doesn't give you 1 M of sulphuric acid, it gives you 1 mol dm-3. Does this matter? Will I still need to dilute it? I was always told by my chemistry teacher not to get moles and moles per dm cubed mixed up - but i never really knew the difference!
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I know theres been quite a bit of help on the concentrations you need, but I just thought I'd point out that it doesn't give you 1 M of sulphuric acid, it gives you 1 mol dm-3. Does this matter? Will I still need to dilute it? I was always told by my chemistry teacher not to get moles and moles per dm cubed mixed up - but i never really knew the difference!
Can you convert the units? What is the textbook definition of M, moles, and "dm-3"?
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looks like we're all stuck with the same planning exercise
I am given aqueous sulphuric acid, of concentration 1.00 mol dm-3
for the titration, is there anything wrong with
H2SO4 + 2NaOH --> Na2SO4 + H2O
im planning on using pthenolpthalein for indicator
i just dont see how it proves its dibasic. will the amount of NaOH just be double the amount of H2SO4? that seems ridiculously easy i must have it wrong :-\
i really dont want to do another titration with HCl and compare
i'd much rather list some calculations
lovely jubbly
what do you think?
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i just dont see how it proves its dibasic. will the amount of NaOH just be double the amount of H2SO4? that seems ridiculously easy i must have it wrong :-\
It does sound easy, but how will you define the amount you'll be "doubling". That may give you the whole answer.
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Do I need do show how much hydrogen is realeased in the gas collection?
If so, how to i do it.
Will it be acceptable for me to do two gas collections one with HCl and one with H2SO4 to show that it is dibasic?
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do you have to draw pH curves in the planning?
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:-X
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just a yes or no would do
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i just dont see how it proves its dibasic. will the amount of NaOH just be double the amount of H2SO4? that seems ridiculously easy i must have it wrong :-\
It does sound easy, but how will you define the amount you'll be "doubling". That may give you the whole answer.
the whole answer :D
i like the sound of that haha
so if H2SO4 and NaOH are both at 1mol/dm concentration
NaOH should be double the amount of H2SO4 to neutralise
but how does that prove that H2SO4 is dibasic?
because... there are two H+ for every OH-?
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so if H2SO4 and NaOH are both at 1mol/dm concentration
NaOH should be double the amount of H2SO4 to neutralise
but how does that prove that H2SO4 is dibasic?
because... there are two H+ for every OH-?
... theoretically, if you have a 1 M HCl and a 1 M NaOH solution, how man H+ per OH would you have?
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so if H2SO4 and NaOH are both at 1mol/dm concentration
NaOH should be double the amount of H2SO4 to neutralise
but how does that prove that H2SO4 is dibasic?
because... there are two H+ for every OH-?
... theoretically, if you have a 1 M HCl and a 1 M NaOH solution, how man H+ per OH would you have?
if it was HCl there would be 1:1
so it should be the same amount of HCl and NaOH to neutralise
will it be enough to say that because 1 mole of H2SO4 reacts with 2 moles of NaOH, it shows its dibasic or would another titration with HCl be necessary?
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No need for another titration, although theoretical discussion will be nice.
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I know theres been quite a bit of help on the concentrations you need, but I just thought I'd point out that it doesn't give you 1 M of sulphuric acid, it gives you 1 mol dm-3. Does this matter? Will I still need to dilute it? I was always told by my chemistry teacher not to get moles and moles per dm cubed mixed up - but i never really knew the difference!
a "mole" is a number, like a dozen
if i say i'll give you a dozen marbles im giving you exactly 12
1 mol dm-3 is the same as saying one mole per decimetre cubed
its a concentration
so in 1 dm3 there is 1 mole, in a 1 mol-dm3 solution
and in 1 dm3 there is 2 moles, in a 2 mol-dm3 solution
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No need for another titration, although theoretical discussion will be nice.
ok thankyou, one other thing
in the gas collection experiment
is there a special name for the bung that goes in a conical flask with a hole in the middle and the tube? (that the Hydrogen will travel through)
:-\
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stumbled across this page and its full of pretty good stuff 8)
in regards to the calculations
on other titrations i have done
you find out how much of the base was needed to neutralise the H2SO4
then you have to multiply this by the conc, which is 1.00
this will give you the amount of moles of base you used
then write a balanced equation of the reaction
to see how many moles of H2SO4 are being used
then use this to work out the Mr
which should show you it is dibasic
hope i wrote it out correctly
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heyho
i dont know whether you guys have taken this into account but make sure you dilute both the H2SO4 and the NAOH in the titration otherwise you wont get any marks for safety...i would dilute both to 0.1moldm3, then the numbers are easier to work with when you multiply back up later on. (and add the water slowly to the sulphuric acid, in case you didnt already know)
for those of you who are reacting with hcl aswell- no need. in the gas experiment if you use a known amount of H2SO4 and react it with excess metal (i would use Mg ribbon) and collect the gas (H2) you can calculate very easily the number of moles hydrogen released per mole of sulphuric acid.
also with the gas experiment mention the use of an ignition tube to make sure all gas is collected..
for the titration, pretty much the same thing. titrate with NAOH at the same conc as the acid (0.1) and record volumes etc. make sure your results are concordant obviously :P then use the RAM of both substances to calculate ratio of moles and whatever...
and earlier on in the thread with the "doesnt prove its diprotic just proves H+ ions are released" or something similar-- that is irrelevant at the level this plan is. the exam board doesnt think we have the capacity to understand that yet. i dont think :P
and the bung with the hole in doesnt really have a name. just make up something complicated like "bung with delivery tube attachment". i reckon.
hope that helped...
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how do i start the actual plan off?
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ive started mine off with an aim
something like, "to show that h2so4 is dibasic by using two different experiments"
then have a heading saying experiment 1 and off you go describing it
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thanks
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Can someone please help me with figuring out the following...
- how to work out the ammount of HCL & H2SO4 needed in the gas collecting experiment.
- How to work out how much Mg is needed in the gas experiment, and how much is excess.
Thanks, and thanks for this thread.
helped so much ;D
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Start with balanced reaction equations. This is simple stoichiometry. You want such a volume of gas to be produced, that it will be easy to measure. Then, you want to use slight excess of Mg to be sure, that all acid reacted.
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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
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If you are titrating with strong base, phenolphthalein will do.
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thanks
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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.
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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
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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!
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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.
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fwww.chemguide.co.uk%2Fphysical%2Facidbaseeqia%2Fsummary.gif&hash=1548b80183e78ec5ae986627eae1e56de978a4ed)
The equivalence point of the strong acid/ strong base titration covers the pH range for both indicators.
Hope that helps out too.
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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.
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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)
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Check pH calculator link from my signature :)
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How are we actualy meant to work out how much sulphuric acid we need for the titration ?
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what type of titration would be best an acid-base titration or a neutralisation titration?
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what type of titration would be best an acid-base titration or a neutralisation titration?
What's the difference?
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oh i thought they were different, but obviously not!
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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!! ;D xxx
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You can work out how many moles of CO2 gas are given off, and compare it to the equation.
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Hi, I've got my method for the titration- I'm titrating sulphuric acid and then comparing that to monobasic HCl but i'm stuck on how to show that it is actually dibasic. IS it that you need twice as much HCl in volume or the moles? I was going to work out the molar masses of each acid used and then see if sulphuric was double hydrochloric using
Molar Mass of acid= concentration x volume / 1000
but i don't know if this is right??? x
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titrate sulphuric acid with NaOH and compare this with HCl. you should see that you need twice as much NaOH to neutralise the H2SO4 then the HCl
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has anyone finished their plan?
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I haven't even started it mate ;)
Neither have a couple of my friends though. I think we're all doing it tomorrow, & then refining it on monday morning before the exam.
Cutting it close, i know, but we love to live on the edge & all that :)
& am I the only one who has never done gas collection before? Not really any idea of how to do a method for it....
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I've finished and handed it in. My school wanted them in crazy early.
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What apparatus do you use for the gas collection? And does anyone else have to write about making their own sodium hydroxide?
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I was talking to my teacher and apparently it is best not u compare with HCl as this doesnt give you an oppurtunity to get marks for mole calculations and that i should just use stoichiometry from "assumed results" of the titration.. so i thought as it is a 2:1 reaction i should assume the volume of acid needed to be half the volume of the NaOH (i am using 25ml) so 12.5 but then what calculations should i do? any help would be realllly appreciated im so stuck! thanks x
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i hope everyone finished their planning and did good in their practical!!! ;D ;D