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Author Topic: What titrations have you tried?  (Read 47049 times)

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Borek

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What titrations have you tried?
« on: March 22, 2006, 01:25:08 AM »

Please list titrations you have done during your chemistry lessons/labs. What have you titrated (vinegar) what you wanted to determine (acetic acid concentration), why your results was wrong (it was red wine vinegar and it masked phenolophtaleine). If your result was correct you may omit last point ;)
« Last Edit: February 21, 2009, 02:55:43 AM by Borek »
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Alberto_Kravina

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Re:What titrations have you tried?
« Reply #1 on: March 23, 2006, 02:04:00 AM »

This might be a quite long list, but anyway....

1.)Calculation of the titre of NaOH and HCl using oxalic acid and sodium carbonate

2.)Determination of the percentage of conc. sulfuric acid with NaOH
Result: 96,37%

3.)Determination of the percentage of Soda w = 30-50 %
Result: 37,89 % (My classmates had similar results...) We also had to draw a titration curve...easy.. ;)

4.)Determination of w[%] of a conc. Soda lye solution w = 30-35% and sodium carbonate impurities (Warder and Winkler method)
Warder method: w(NaOH)=31,67%    w(Na2CO3)= 3,85 %
Winkler method: w(NaOH)=32,20%    w(Na2CO3)= 3,45 %

4.)Determination of percentage of acetic acid in vinegar:
Nothing went wrong since it was white vinegar- Result: 4,93% (On the label it said 5% )

5.)Calculation of the titre of a KMnO4 solution: Nothing went wrong

6.)Determination of w[%](H2O2) (manganometric)
Result: w= 35,20%

6.)Determination of Nitrite in a NaCl-NaNO2 mixture
Result: 2,96%

7.)Determination of perborate (in a washing powder) and potassium persulfate (back titration)

w(Na-perborate)= 14,53 % (on the label it said "5-15%" sodium perborate)

Hmmmm..persulfate...this went wrong: it was a p.a. Potassium persulfate but my result was 88,43%. :cryss:

8.)Method Vollhardt-Wolff....It was pretty difficult to catch the endpoint. Result: 99,12% (I analyzed a p.a.MnSO4)

9.)Analysis of Ca2+ in milk with EDTA...result: 1,205 g/L Ca2+
see also: http://www.chemicalforums.com/index.php?board=8;action=display;threadid=7158

10.)Iodometry: Calculation of the titre of a thiosulfate solution with potassium iodate: nothing went wrong.

11.)Determination of H2O2 (actually the same H2O2 solution that I analyzed during manganometry)
Result: 35,91%

12.)Determination of a chlorine bleach solution:
Result: 35,47 g/L

13.)Analysis of a satured Formaldehyde solution (back titration):
Result: 36,78%

14)Argentometry: Mohr method to determine w(NaCl) in a mixture of sand and salt:
Result: 69,04%  

I performed a few others such as Reinhardt-Zimmermann method  and Haen-Low method (analysis of Copper), but there was nothing special..
« Last Edit: March 23, 2006, 04:42:38 AM by Alberto_Kravina »
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Borek

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Re:What titrations have you tried?
« Reply #2 on: March 25, 2006, 06:36:50 AM »

Do you have lab manuals for these (in some widely accepted and understood language ;) )?
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Alberto_Kravina

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Re:What titrations have you tried?
« Reply #3 on: March 26, 2006, 12:42:11 AM »

Do you have lab manuals for these (in some widely accepted and understood language ;) )?
I have a manual where "millions" of titrations are listed  Unfortunately this manual is written in an ununderstandable language, ( German ;) )
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Borek

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Re:What titrations have you tried?
« Reply #4 on: March 26, 2006, 12:50:02 AM »

I have a manual where "millions" of titrations are listed  Unfortunately this manual is written in an ununderstandable language, ( German ;) )

Paper or electronic form?
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Alberto_Kravina

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Re:What titrations have you tried?
« Reply #5 on: March 26, 2006, 12:51:53 AM »

Paper! But I programmed an Excel program by myself to calculate the results.
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Alberto_Kravina

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Re:What titrations have you tried?
« Reply #6 on: March 26, 2006, 01:33:10 AM »

Just if someone would be interested: the manuals are:

1.)Jander Jahr - Massanalyse (There you can find EVERYTHING about titrations, but it is a bit expensive.... :P)

2.)A. Berger, Band 2, Quantitative analysen (In this manual you'll find Gravimetry, Volumetry and Photometry), it's a very good book.

But as I said German is not understandable for most people on earth ;)
« Last Edit: June 02, 2006, 02:30:19 AM by Alberto_Kravina »
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Borek

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Re:What titrations have you tried?
« Reply #7 on: March 26, 2006, 02:17:23 AM »

Paper! But I programmed an Excel program by myself to calculate the results.

You can use EBAS for exactly the same thing :)
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lemonoman

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Re:What titrations have you tried?
« Reply #8 on: March 26, 2006, 10:19:13 AM »

Getting back on topic :P I've done quite a few different kinds of titrations...

classic acid/base (too many to list)
voltametric (determining Cl- and I- by titration with AgNO3
coulometric (determining arsenic concentration with Iodine)
thermometric (Determining Hydrochloric and Acetic Acid conc. with NaOH)
conductometric (Determining Pyridine and Tris conc. with HCl)
spectrophotometric (determining KHP conc. with...I forget)
EDTA (ligand/substrate) (We did Zinc, but obviously EDTA does way more)

and probably some others that don't come to mind.

I don't have a particular manual for doing all kinds of titrations...but one comes to mind....

Vogel's Quantitative Inorganic Analysis is definitely a good one.  I remember we neede to find out how to determine Zinc in a solution (left over from determining other components of brass).  So I looked up "Zinc" in the glossary and it gave me like, a dozen ways to do it!  The older editions (like 3rd) are better...because after that they started replacing tried-and-tested techniques with high-tech ones and more information :(

Hope that helps!
« Last Edit: March 26, 2006, 10:24:06 AM by lemonoman »
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Albert

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Re: What titrations have you tried?
« Reply #9 on: April 27, 2006, 09:53:32 AM »

Last term I carried out the following titrations.

Nov 2
Standardization of NaOH solution with KDA
Result: 0.09920 N

Nov 3
Determination of w/w% of citric acid, monohydrate
Result: 100.7%

Determination of w/w% of phosphoric acid
Result: 84.30%

Nov 4
Potentiometric titration
Determination of the normality of NaOH solution
Result: 0.09869N

Nov 7
Conductometric titrations
Determination of the normality of HCl solution
Result: 0.1000N (superb!) ;D

Determination of w/w% of sodium acetate anhydrus
Result: 94.62%

Nov 8
Determination of w/w% of Tartaric acid
Result: 100.8%

Determination of w/w% of Tartaric acid in a sample
Result: 1.241% (my ONLY mistake: it was 1.267%)

Nov 9
Standardization of a AgNO3 solution following the European Pharmacopoeia (Mohr)
Result: 0.1005N

Determination of w/w% of NaCl (Fajans)
Result: 100.3%

Determination of w/w% of KBr (Fajans)
Result: 99.49%

Determination of w/w% of KI (Fajans)
Result: 99.17%

Nov 10
Determination of w/v% of NaCl in a sample (Mohr)
Result: 0.8458g/100mL

Determination of w/w% of NaCl in another sample (Vohlard)
Result: 98.16%

Nov 11
Standardization of a HClO4 solution in acetic acid with POTASSIUM ACID PHTHALATE
Result: 0.1008N

Determination of w/w% of lidocaine chloridrate, anhydrous (using the aforementioned HClO4)
Result: 100.6%

Determination of w/w% of alanine
Result: 99.93%

Nov 14
Standardization of CH3ONa solution with benzoic acid
Result: 0.1004N

Determination of w/w% of sulfamethoxazole with CH3ONa
Result: 100.1% (I was the best one!)

Nov 15
Standardization of KMnO4 with oxalic acid dihydrate
Result: 0.1007N

Standardization of a Na2S2O3 solution with the aforementioned KMnO4
Result: 0.1017N

Nov 16
Determination of w/v% of H2O2 in a sample with KMnO4
Result: 0.3274g/100mL

Determination of w/w% of CuSO4.5H2O with Na2S2O3
Result: 99.62%

Determination of w/w% of KIO3 with Na2S2O3
Result: 100.3%

Nov 17
Determination of w/v% of KIO3 in a sample with Na2S2O3
Result: 0.5650g/100mL

Standardization of an EDTA solution with CaCO3 (direct method)
Result: 0.1002M

Nov 18
Standardization of an EDTA solution with CaCO3 (using Eriochrome Black T)
Result: 0.1001M

Determination of w/w% of MgSO4.7H2O with the solution of EDTA already titrated
Result: 99.60%

Determination of w/w% of ZnO with EDTA
Result: 99.26%

Nov 21
Determination of w/w% of MgO with EDTA
Result: 98.64%

Determination of w/v% of CaCO3 in a sample with EDTA (using Eriochrome Black T)
Result: 1.962g/100mL

Then, we started spectrophotometric determinations.
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Will

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Re: What titrations have you tried?
« Reply #10 on: May 18, 2006, 10:30:04 AM »

I once did an experiment to determine the % Cu in brass- and you end up with CuI and I2 in this strange coloured solution.
The titration to find the moles I2 (with thiosulfate) is quite difficult because the colour change is so faint. Using starch towards the end (as an indicator) didn't help :(. I just worked backwards, by guessing the percentage of copper in the brass screw using my friend google, which gave me the 'right' titration result (since the % was spot on!). ;D
I never want to do that titration again!
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mookxi

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Re: What titrations have you tried?
« Reply #11 on: June 01, 2006, 08:20:46 PM »

Please list titrations you have done during your chemistry lessons/labs. What have you titrated (vinegar) what you wanted to determine (acetic acid concentration), why your results was wrong (it was red wine vinegar and it masked phenolophtaleine). If your result was correct you may omit last point ;)

1. Standardisation of 0.1M HCl solution

We found the concentration to be 0.112M which could have been due to foreign substances which may still have been left in the conical flask which effects the end point (titre volume)

2. Determination of acetic acid in vinegar

3. Analysis of ammonium content in lawn feed (NH4)2SO4 - a back titration
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Alberto_Kravina

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Re: What titrations have you tried?
« Reply #12 on: June 02, 2006, 07:32:51 AM »

The one I performed two days ago: Determination of w/w%(NaClO2) (w= 70-80%)

Result: 72.36%

Nothing special to report about this titration... :P
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firzzy87

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Re: What titrations have you tried?
« Reply #13 on: August 05, 2006, 10:43:28 PM »

Titration with NaoH and KHP ... Is KHP strong acid ???
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Borek

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Re: What titrations have you tried?
« Reply #14 on: August 05, 2006, 11:09:59 PM »

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