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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: Borek on March 22, 2006, 01:25:08 AM

Title: What titrations have you tried?
Post by: Borek on March 22, 2006, 01:25:08 AM
Please list titration (http://www.titrations.info)s 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 ;)
Title: Re:What titrations have you tried?
Post by: Alberto_Kravina 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..
Title: Re:What titrations have you tried?
Post by: Borek on March 25, 2006, 06:36:50 AM
Do you have lab manuals for these (in some widely accepted and understood language ;) )?
Title: Re:What titrations have you tried?
Post by: Alberto_Kravina 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 ;) )
Title: Re:What titrations have you tried?
Post by: Borek 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?
Title: Re:What titrations have you tried?
Post by: Alberto_Kravina on March 26, 2006, 12:51:53 AM
Paper! But I programmed an Excel program by myself to calculate the results.
Title: Re:What titrations have you tried?
Post by: Alberto_Kravina 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 ;)
Title: Re:What titrations have you tried?
Post by: Borek 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 :)
Title: Re:What titrations have you tried?
Post by: lemonoman 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 (http://www.amazon.com/gp/product/0582226287/102-1451609-3573765?v=glance&n=283155) 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!
Title: Re: What titrations have you tried?
Post by: Albert 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.
Title: Re: What titrations have you tried?
Post by: Will 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!
Title: Re: What titrations have you tried?
Post by: mookxi 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
Title: Re: What titrations have you tried?
Post by: Alberto_Kravina 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
Title: Re: What titrations have you tried?
Post by: firzzy87 on August 05, 2006, 10:43:28 PM
Titration with NaoH and KHP ... Is KHP strong acid ???
Title: Re: What titrations have you tried?
Post by: Borek on August 05, 2006, 11:09:59 PM
Is KHP strong acid ???

No.
Title: Re: What titrations have you tried?
Post by: firzzy87 on August 07, 2006, 12:53:34 AM
so it is titration between strong acid and weak base , right
Title: Re: What titrations have you tried?
Post by: Borek on August 07, 2006, 01:14:08 AM
so it is titration between strong acid and weak base , right

Yes. Ka1 = 2.95, Ka2 = 5.41. Note only the second dissociation constant is of interest to you, as you start with half neutralized salt (hydrogen phthalate) so your titration curve should look like the part with bluish tint below (both concentrations assumed 0.1M).

BATE rulez ;)
Title: Re: What titrations have you tried?
Post by: Will on August 07, 2006, 01:26:56 AM
so it is titration between strong acid and weak base , right

Yes.

Are you being sarcastic? ;)
Title: Re: What titrations have you tried?
Post by: elmyhalily13 on October 06, 2006, 03:09:02 AM
I have done titrations for H2S, Mercaptans and chloride. I use Silver Nitrate as titrant. The end point is determined using autotitration probe. For chlride the procedure is simple as the procedure can be done directly. But for Mercaptans and H2S, sample preparation need to be done. As the samples are gases they are flowed through sodium hydroxide or potassium hydroxide so that they can dissolve. Then only the testing is done.

Regards,

Elmy Halily
Title: Re: What titrations have you tried?
Post by: zaied9 on November 24, 2006, 07:28:18 AM
I have tried the following titrations:
          1) Neutralization titration of
            @Standardization of HCl using 0.1M Na2CO3 standard solution
            @Determination of the concentration of sodium hydroxide solution using a standard solution of hydrochloric acid
            @Analysis of vinegar
           
           2) pH Metric titration of NaOH with a standard solution of HCl
           
            3) Redox Titration
                i. standardization of KMnO4 solution by using a standard solution of
                    oxalic acid
               ii.Determination the concentrarion of FeSO4 solution by using a standard solution of KMnO4
           
                   I know this is so easy but I m a first year student at the faculty of science, but the
               difficult is getting nearer as im s biotechnology student. ;)
                                                                                                       Mamin Zaied
             
Title: Re: What titrations have you tried?
Post by: dfx- on December 22, 2006, 12:39:43 PM
I know this is so easy but I m a first year student at the faculty of science...

Is it just my degree course or is it common for chemistry degrees to basically stop doing titrations at all after first year? I can't remember most of the ones I've done as a result..

Title: Re: What titrations have you tried?
Post by: english on December 23, 2006, 02:01:42 AM
I know this is so easy but I m a first year student at the faculty of science...

Is it just my degree course or is it common for chemistry degrees to basically stop doing titrations at all after first year? I can't remember most of the ones I've done as a result..



Pretty much.  Haha, kind of true. 
Title: Re: What titrations have you tried?
Post by: AhmedEzatAlzawalaty on March 15, 2007, 10:56:35 AM
i have titrated
lead REDOX
Mn,Al,Ca,Mg,Zn,Cu, COMPLEXIMETRY
Acids,Water analysis
Title: Re: What titrations have you tried?
Post by: AhmedEzatAlzawalaty on March 26, 2007, 05:27:10 AM
recently i did Argentometric Volhard , Fajan and Mohr methods and i also titrated KCl with HgCl2 u know  (the titrant is titrated with analyte)
Title: Re: What titrations have you tried?
Post by: UnintentionalChaos on May 28, 2007, 10:30:38 AM
Total acid content of grape juice to be made into wine (expressed as grams of tartaric acid equivalent per 100ml). My uncle makes his own wine and has to rely on a wine school to do the testing of the grape juice for him, which is sometimes an inconvienance. The idea is that the acid content of grapes varies (varying mixes of mostly tartaric, some malic, and some citric acid, which makes an endpoint a pain in the ass to find) and there is an ideal acidity for each type of wine. After seeing that the wine shcool gives acid adjustments in 100ml of Tartaric acid portions (yes, I said ml...the lack of accuracy scares me), I was very much compelled to do the testing myself. So, NaOH solution at 0.05M and titrated 10ml samples a few times, screwing up the endpoint because the grape juice messes with the phenolphthalein. If you dilute the sample and use a hefty number of phenolphthalein drops, there is an definite endpoint although it is not too sharp (for these purposes, a few drops either way doesn't really mean much). So I have Molarity of the hydronium ion concentration and I need something they call total acid content. It took me a few hours to decipher that this meant "Pretend all the hydronium ions come from tartaric acid and convert to grams/100ml" I got 0.55 which is quite low for making any wine and justified the addition of tartaric acid (although I doubt that the prescribed addition was anything close to what it should have been). I've done several other, but this was the most interesting (and citizen chemistry)
Title: Re: What titrations have you tried?
Post by: firzzy87 on July 30, 2007, 02:54:32 AM
i've tried regularly the standardization of NaOH with KHP... Great .. It's not easy to get a very pale pink...  ;)
Title: Re: What titrations have you tried?
Post by: UnintentionalChaos on October 24, 2007, 04:45:45 PM
Putting the beaker/flask on a sheet of white office paper helps me spot the endpoint.  ;)
Title: Re: What titrations have you tried?
Post by: chrisbb on March 10, 2008, 06:56:30 AM
im an undergrad student and im in a 3 year program. I am still doing titrations, and i'm almost ready to snap. At least its not standardization of HCl & NaOH :D
Title: Re: What titrations have you tried?
Post by: alhemicar on March 26, 2008, 08:41:48 AM
I have done too much titrations  8)

acids : standardization NaOH, HCl,  Na2B4O7 and H3BO3 mixed, H2SO4, standardization HClO4,...

COMPLEXIMETRY: Ca, Ca and Mg mixed, Cu and Zn mixed, Mg and Pb and CU and Zn mixed, Cu and Pb mixed...

Oxido : Standardization KMnO4, Fe (with KMnO4) , standardization Na2S2O3, Cu, Fe (with K2Cr2O7), C2H8O6 standardization, Fe (with C2H8O6)

Mohr: Cl

Title: Re: What titrations have you tried?
Post by: yy on April 03, 2009, 02:00:44 AM
Recent one is:
Determining salt content in dried soup powder by Potentiometric Titration.

Titrant AgNO3 (0.1M)
Standard Solution NaCl (0.1M)
Sample: 10 g dried soup powder.
AgCl electrode.

[Salt/NaCl]in sample: 0.1521M
grams of NaCl in 10gSample: 1.065g

Manufacturer's spec. (Sodium/Na) Per serving, 285mg/100mL.

...and I am in the middle of figuring out how to compare the result with the spec. :P  One thing to watch out is though, Manufacturer spec only gives sodium content, than NaCl. A trick often played by corporations!
Title: Re: What titrations have you tried?
Post by: Borek on April 03, 2009, 03:00:03 AM
Determining salt content in dried soup powder by Potentiometric Titration.

Titrant AgNO3 (0.1M)

That's not (kitchen) salt determination, that's chlorides determination (or, more precisely, sum of chlorides, bromides and iodides).

Quote
Manufacturer spec only gives sodium content, than NaCl. A trick often played by corporations!

It is sodium that has to be controlled in your diet. Where is the trick?
Title: Re: What titrations have you tried?
Post by: Fridushka on August 30, 2009, 01:43:51 PM
precipitation titration: preparation and standardization of silver nitrate and potassium thiocyanate solution and determination of chloride in an unknown sample.
We used Fajnas and Mohr methods and got the average [Ag+]=0.106665 mol/L
after which we find the mCl-= 0.06247g
the [SCN-]= 0.10602 mol/L
then we used Volhard method to determine the %Cl in the unknown sample which was equal to 52.74%

Complexation Titration: preaparation and standadization of EDTA solution, & determination of total Hardness of water.
1st of all, we calculated the average concetration of EDTA=  9.2x10-3 then we found the [CaCO3]=0.001160701 mol/L, and we got the its mass to be equal to ~ 11.62 mg

Redox titration: preparation and standadizationv of a potassium permaganate solution and determination of the percentage of Oxalate in an unkown sample.
[Mno4-]=0.018M, while the oxalte; [C2O42-]= 0.0179M
then we get the %C2O42-=48.513% with an error of + or - 4!
Title: Re: What titrations have you tried?
Post by: Ida Isotope on August 31, 2009, 04:29:46 AM
Off the top of my head I recall using potassium permanganate alot. As well as HCl and NaOH.
Title: Re: What titrations have you tried?
Post by: blurry on February 07, 2010, 12:57:03 AM
finding amount of sugar in apple juice

finding number of moles of NaOH needed to neutralize HCl

finding amount of CaCO3 in an eggshell

analysis of aspirin tablet

standardization of potassium hydrogenphthalate and using it in order to determine concentration of a solution of NaOH

determination of the relative molecular mass of a group 2 carbonate.

i must say the actual experiment is quite fun, but the calculations are rather annoying. and im still in high school! cant imagine what uni will be like.
Title: Re: What titrations have you tried?/ZnO
Post by: Golden_4_Life on August 06, 2010, 05:32:14 AM
We titrated 3 times a sample of diaper rash cream that was labelled as "20.5% ZnO", our results indicated tha the cream had 30.1% ZnO.  The method we used was USP (with  inidcator =eriochrome black t.s. and chelator = EDTA).
1) why would such a disparity in quants be observed?
2) could the product label value be wrong?
3) we believe our assay is valid as it was "method validated" but only to 5% wt. ZnO.
4) but regardless, isn't it a linear assay up to and way above 5% anyway? So, the same assay should work for a 20% conc. level no?

Thanks in advance for any insights,
G-4-L.
Title: Re: What titrations have you tried?
Post by: Mr Lead on September 30, 2010, 10:35:51 AM
First of all: sorry bad English

I have tried different tipologies of titrations:
1-Ordinary standardization of a strong acid (HCl,with sodium carbonate) and a strong base (NaOH,with  acid phtalate of potassium).When titrated HCl with NaOH, we had to show graphically the effect on the titration curve of the difference of concentration between acid and base.

Titrations I like very much:
2-Titration of the % of acetic acid in vinegar- White vinegar to see a better colour change.
3-Titration of dissolved O2 in river and lake water by Winkler method.Difficult add reagents to glassworks.
4-Potentiometric titration of Fe2+ to Fe3+ with KMnO4
5-Fajans quantitative determination of chloryde ions - Difficult to see change of colour
6-Quantitative determination of Ca2+ and Mg2+ simultaneously by complexometric titration with EDTA
7-Titration to calculate the pKa1 and pKa2 value of aspartic acid
8-Titration of H2O2 with iodometric titration - less interferences in comparison with mangametric
9-Iron determination by Zimmermann titration
10-Titration  of carbonate-bicarbonate mixture
11-Conductometric titration of Cl- with solid electrode-

Sometimes difficult to built curve and calculate final point with "Gran Method" for weak acids or different graph methods of determianation.I like titrations very much.
Nowadays analytical chemistry seems to be only instrumental analysis..but i feel chemistry in titration =))
Title: Re: What titrations have you tried?
Post by: Pradeep on December 16, 2010, 06:25:08 AM
I have done, Acid- Base + Redox, Iodometric, Iodimetric, Complexo metric, Non aqous and  cloulomtric titrations.
Title: Re: What titrations have you tried?
Post by: sschoe2 on April 29, 2013, 10:03:27 AM
I've done countless titrations as a TA for gen chem and also at my job.

My most frequent titration I do today is titration Cl- ions with AgNO3. To determine the salt content in foods it is dissolved in acidic water and AgNO3 is added. It reacts with the Cl- ions to form insoluble AgCl and with the removal of the Cl- from the water the conductivity of the solution is reduced which is detected by an electrode in the solution.

I also frequently titrate weak acids like malic with NaOH to get total acidity.

Another interesting one is the titration of ethanol with Cr (IV).
http://www.chem.uic.edu/chem114/LAB/ethanol_oxidation.pdf
it was a undergrad lab in kinetics when I taught but for all you boozers it is the basis for Breathilizers used by cops.
Title: Re: What titrations have you tried?
Post by: mohsendm on July 16, 2013, 10:57:14 PM
titration HCL with NaOH to determinate PH.
Title: Re: What titrations have you tried?
Post by: 408 on July 17, 2013, 08:06:12 AM
Hypofluorous acid with thiosulfate and iodide to determine concentration. 
Title: Re: What titrations have you tried?
Post by: sarahbarkson on July 21, 2013, 03:12:59 AM
neutralisations
Title: Re: What titrations have you tried?
Post by: adamvid on February 15, 2014, 11:51:19 AM
Hi
Paper or electronic form  ?
Title: Re: What titrations have you tried?
Post by: Borek on February 15, 2014, 09:35:10 PM
The real thing only.
Title: Re: What titrations have you tried?
Post by: Xenonman on April 08, 2014, 04:30:54 PM
The usual NaOH and HCl ones. I think I've done most of those correctly.
Na2CO3 with HCl and H2In+Methyl red. That one was horrible  >:( the color change wasn't what I expected.  A mess.
Iodine-in-cleaning-products titration with sulphite and starch. That was the best one. One drop changed the solution from pitch-black to transparent.
Boric acid and mannitol made a weird, monoprotic complex which removed all the fun. We even used H2In again. No new reaction, no new indicator, no new colors. That could have been any other acid and we'd never have known.
Volhard and Mohr's. We all expected a blood red color for the end point because the procedure said that. Turns out the the end point has a faint orange color, not a blood red one. Mohr's was much friendlier.
Title: Re: What titrations have you tried?
Post by: cseil on August 17, 2014, 01:35:35 AM
I don't have the results (I'm not home right now).
I did these titrations during the course of Analytical Chemistry I.

Acid-base

NaOH with KHP
HCl with C4H11NO3
Determination of the percentage of HCO3- and CO32- into a solid mixture (unknown)

Complexometry

Na2H2EDTA with CaCO3
Determination of the percentage of Ca2+ and Mg2+ into a sample of mineral water

Precipitation

AgNO3 with NaCl
Determination of the concentration of Cl- into a sample of water (Mohr's method)
KSCN with AgNO3
Determination of the concentration of Cl- into a sample of water (Volhard's method)

Redox

KMnO4 with Na2C2O4
Determination of the percentage of H2O2 into a disinfectant (I used KMnO4)
Na2S2O3 with K2Cr2O7
KMnO4 with Na2S2O3 (iodometric)
Determination of NaOCl into a sample of bleach for domestic use
Determination of the percentage of ascorbic acid into a nutritional supplement