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Titration Graphing Results (Need Help) (1 Viewer)

BlueGas

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I need help in graphing these results (need a graph for each result, or if you can just make one graph and tell me how to do it for the rest), I want that graph to look like the graph I included, thank you very much if you help, would really appreciate. The solutions HCL and sodium carbonate were used in the titration.

The results:

Result 1:

CA = 0.98 CB = 0.5 VA = 0.0255L VB = 0.025L

Result 2: CA = 1.5 CB = 0.1 VA = 0.00315L VB = 0.025L


Result 3: CA = 1.04 CB = 0.1 VA = 0.0048L VB = 0.0025L

The graph I want it to look like:

 

Crisium

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Lol Ahmad Shah Idil's Notes

Search up titration grapher and you should find one
 

BlueGas

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Lol Ahmad Shah Idil's Notes

Search up titration grapher and you should find one
I see that all graphs have on the vertical axis "pH", how do I find the pH of NA2CO3? Am I meant to find the pH of that or HCL?
 

Crisium

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I see that all graphs have on the vertical axis "pH", how do I find the pH of NA2CO3? Am I meant to find the pH of that or HCL?
You're meant to know / find out the volume of the ACID added because the sodium carbonate is being titrated by that (Notice that the x-axis says "Volume of Acid Added", so you should deduce from that,that you must find the pH of the acid)

In regards to finding the pH though I honestly don't see how you could draw up a graph like this without the aid of a data logger and a pH meter, unless you did use them.

^ This is because they monitor the change in pH as the solution is titrated and from the graph, the equivelance point occurs at the point of inflexion of the graph
 

BlueGas

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You're meant to know / find out the volume of the ACID added because the sodium carbonate is being titrated by that (Notice that the x-axis says "Volume of Acid Added", so you should deduce from that,that you must find the pH of the acid)

In regards to finding the pH though I honestly don't see how you could draw up a graph like this without the aid of a data logger and a pH meter, unless you did use them.

^ This is because they monitor the change in pH as the solution is titrated and from the graph, the equivelance point occurs at the point of inflexion of the graph
Well I didn't use a data logger or a pH meter so that means I can't use pH in my graph. The criteria of my report is asking that to "provide a graph of results", my results are mentioned above so how would I graph them?
 

Fiction

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I need help in graphing these results (need a graph for each result, or if you can just make one graph and tell me how to do it for the rest), I want that graph to look like the graph I included, thank you very much if you help, would really appreciate. The solutions HCL and sodium carbonate were used in the titration.

The results:

Result 1:

CA = 0.98 CB = 0.5 VA = 0.0255L VB = 0.025L

Result 2: CA = 1.5 CB = 0.1 VA = 0.00315L VB = 0.025L


Result 3: CA = 1.04 CB = 0.1 VA = 0.0048L VB = 0.0025L

The graph I want it to look like:

Usually graphs of titration have titrant added (units) on the x-axis and pH on the y axis. they have the general shape that you have in the graph above, but it can be flipped, depending on whether you have a strong acid or weak acid as your titrant.

So for example (assuming your base is your titrant, and your acid is your analyte)

for result 1:
CA = 0.98 CB = 0.5 VA = 0.0255L VB = 0.025L

to find the pH of your acid --> -log( [H+] )
= - log ( 0.98 *1 )

then use whatever value you got from ^ to start your curve off with. Since it's a strong acid and weak base, then the point of equivalence will be below pH 7 - so your inflexion point or the steepest part of your graph is located below pH 7. Then find the pH of your base and that's the point where the graph will level out to be.

If you want to add buffers, for the above graph it'll be on the points after the inflexion point, where your graph is approaching the base's pH if that makes sense.

Hope that helped :)
 

Fiction

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You're meant to know / find out the volume of the ACID added because the sodium carbonate is being titrated by that (Notice that the x-axis says "Volume of Acid Added", so you should deduce from that,that you must find the pH of the acid)

In regards to finding the pH though I honestly don't see how you could draw up a graph like this without the aid of a data logger and a pH meter, unless you did use them.

^ This is because they monitor the change in pH as the solution is titrated and from the graph, the equivelance point occurs at the point of inflexion of the graph
The point of equivalence for a valid titration experiment is meant to be as close to the end point as possible. Thus you could use an indicator to draw this graph, it won't be as accurate as using a data logger and pH meter, but you should still be able to do it.
 

BlueGas

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Usually graphs of titration have titrant added (units) on the x-axis and pH on the y axis. they have the general shape that you have in the graph above, but it can be flipped, depending on whether you have a strong acid or weak acid as your titrant.

So for example (assuming your base is your titrant, and your acid is your analyte)

for result 1:
CA = 0.98 CB = 0.5 VA = 0.0255L VB = 0.025L

to find the pH of your acid --> -log( [H+] )
= - log ( 0.98 *1 )

then use whatever value you got from ^ to start your curve off with. Since it's a strong acid and weak base, then the point of equivalence will be below pH 7 - so your inflexion point or the steepest part of your graph is located below pH 7. Then find the pH of your base and that's the point where the graph will level out to be.

If you want to add buffers, for the above graph it'll be on the points after the inflexion point, where your graph is approaching the base's pH if that makes sense.

Hope that helped :)
So will I have a separate graph on pH of the base? Because I can't do pH of the base and acid on the same graph right?
 

Fiction

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So will I have a separate graph on pH of the base? Because I can't do pH of the base and acid on the same graph right?
uh what?

You're trying to graph the change in pH - to do it, you need to compare an acid to a base. Assuming it's the base you're putting into the burette, then the base's pH will be the point where it starts to level out again.

For example - look at the graph you posted. The acid acts as the titrant in this case, and the base as the analyte.

0.0 on the x-axis is the pH of your base - however, as you move across to the right on the x-axis, the graph drops (because you're adding in acid and hence lowering the pH) The graph then drops suddenly and then goes into a gentle slopey curve thing and levels out (at approx 0.22 on the x-axis) The point where it levels out completely would be the pH of your acid.
 

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The point of equivalence for a valid titration experiment is meant to be as close to the end point as possible. Thus you could use an indicator to draw this graph, it won't be as accurate as using a data logger and pH meter, but you should still be able to do it.
True but even the general shape of the graph will require dot point approximations for the pH :/
 

BlueGas

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Basically the graph would look like this but different numbers for the x-axis, what would the numbers be?

 
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BlueGas

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Can anyone help me with graphing? When I tried graphing on Excel the graph looked no where near the graph I included above.
 

BlueGas

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Howcome on Ahmad Shah's graph they're recorded incorrectly?

For example, 0.016,

pH = -log (0.016) = 1.8

But on the graph it's recorded differently, I don't understand.
 

Fiction

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True but even the general shape of the graph will require dot point approximations for the pH :/
uh, no? I'm fairly sure the shape of titration curves all look like the example bluegas posed, with only small variations e.g flipped, approximately where equivalence point lies, steepness of curve etc

Basically the graph would look like this but different numbers for the x-axis, what would the numbers be?

What do you mean by 'the numbers'? if you're puzzled about the numbers on the x-axis, the x-axis shows the volume of titrant (stuff in the burette) added to the solution - so it depends on your result. E.g if it took 35ml of titrant to bring about the equivalence point, then the steepest part of your graph will have a coordinate of (35, ___) where the ___ depends on what kind of acid/base you're titrating with.
 

BlueGas

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How do I answer Question 1 and 2 of the picture below? Is the answer for Question 1 the same as Question 2? I feel like the answer is in original post but I'm not sure, need help.

EDIT: I would also appreciate if someone can tell me why we used the indicator "methyl orange" in the experiment, thanks (I honestly don't know).

 

trumanblack

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Depends on what the 'solution' Q2 is referring to, i.e. did you for some reason dilute the given solution of HCl before performing the titration?

You used methyl orange because the titration was between: strong acid (HCl) and a weak base (Na2CO3) thus an acidic salt was produced from the neutralization reaction. As a result, the solution in the conical flask was acidic at/around the the equivalence point and so you needed an indicator that changed colours within the acidic range, i.e. methyl orange.

For extra points you could show that the salt produced is acidic.
 

BlueGas

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Depends on what the 'solution' Q2 is referring to, i.e. did you for some reason dilute the given solution of HCl before performing the titration?

You used methyl orange because the titration was between: strong acid (HCl) and a weak base (Na2CO3) thus an acidic salt was produced from the neutralization reaction. As a result, the solution in the conical flask was acidic at/around the the equivalence point and so you needed an indicator that changed colours within the acidic range, i.e. methyl orange.

For extra points you could show that the salt produced is acidic.
I think the solution the question is talking about is sodium carbonate. Also I didn't dilute HCL with water in the whole experiment.
 

trumanblack

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Oh wait, sorry I missed the point. Point 1 is not a question (I'm thinking) - it's asking you to perform the titration. Then Q2 is where the calculation of the unknown concentration (in this case HCl) comes in. Haha sorry for the mix up
 

BlueGas

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Oh wait, sorry I missed the point. Point 1 is not a question (I'm thinking) - it's asking you to perform the titration. Then Q2 is where the calculation of the unknown concentration (in this case HCl) comes in. Haha sorry for the mix up
Isn't question 1 asking you to determine the concentration of HCL? Then Question 2 is asking calculate the concentration of HCL, I'm confused because I feel like the two questions are asking for the same answer. Well isn't the answer in my original post? For example, in Result 1, the answer for both questions 1 and 2 would be CA = 0.98?
 

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