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Questions tagged [titration]

A laboratory method to determine the concentration of an analyte in solution. The solution volume plays a key role in the analysis.

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Brown color at end point during titration with phenolphthalein as indicator

We did a titration experiment at school and I did not understand one part of it. The scenario: Titrate : White wine (ethanoic acid) Titrant: $\ce{NaOH}$ Indicator: Phenolphthalein What happened: We carried out the titration and the end point…
Bad at chemistry
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Weighing by difference

When preparing a known mass of something (e.g. when producing a standard solution) it is often that in my school lab that we first use a weighing boat to measure the mass and then once transferred into a beaker we reweigh the boat and calculate the…
Jake
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Why does the pH before the equivalence point of a titration depend on the initial concentration only when the acid is strong?

SO, in this picture, two different titration curves are shown: one for a weak acid, one for a strong acid. I'm confused as to why for a strong acid, if you vary the concentration of the acid, (and the concentration of the acid and titrant are the…
Brayden Murphy
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What is the cost of 1.00 g of calcium ions as provided by this brand of dry milk?

A student determined the $\ce{Ca^{2+}}$ ion content in a sample of nonfat dry milk. For complete titration of the $\ce{Ca^{2+}}$ ion present, a sample weighting $1.483 ~\mathrm{g}$ required $41.33 ~\mathrm{mL}$ of $1.183 \times 10^{-2} ~\mathrm{M}$…
user4595
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Rationale for titant standardization in alkalinity measurements [ISO 9963-1:1994]

I work in a environmental chemistry laboratory and I will start to do some alkalinity measurements in my project. My research group is pretty big on following any and all standardization possible, which most often mean compliance according to…
NFA
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What does it mean to take reading up to 0.05 mL?

In titration we usually take burette reading upto $0.01~\mathrm{mL}$, but my teacher says that we need to take reading up to $0.05~\mathrm{mL}$. What does that mean? Does it mean if I read $23.56~\mathrm{mL}$ that I should record it as…
Irtiza
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Why is Lanthanum a "fluoride ion sensitive electrode" and hence used for measuring "flouride concentration"?

My chemistry text book says that "Atomic Absorption Spectrometry (AAS) can be used to determine the concentration of metal ions, but other methods must be used for anions. One convenient method is to use an ion-selective electrode (ISE)." What is…
bman
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What does the small, steep curve at the very beginning of a weak acid strong base titration curve come from?

I understand that a buffer solution is being made, but I don't understand why the titration curve is different from a strong acid strong base one (apart from the steeper pH change). I understand the half-equivalence point and the rest of the…
Jesper2k
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How to find the vitamin C content of orange juice?

I'm an IB chemistry SL student doing an IA on the vitamin C concentration of orange juice. We haven't learned about the titration process, so here is what I have done so far: $\ce{5KI + KIO3 + 3H2SO4 -> 3I2 + 3K2SO4 + 3H2O}$ This is the equation for…
fidafa123
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Titration with EDTA and Eriochrome black T

I have a titration of Calcium Ions with EDTA. When I reach a volume of 9.6mL I the liquid turns slightly blue and after that the more I add the bluer it becomes. Now at what point is my titration finished? When I notice the first change or as soon…
newToEverything
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Why rinse flask with distilled water when the flask will be used for storing aliquots of HCl for titration?

In an experiment for standardisation of NaOH with titration, the lab manual instructed students to rinse conical flasks that were supposed to store 1mL aliquots of hydrochloric acid with distilled water. Won't the excess water dilute the aliquot?…
Bryan
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Phosphoric Acid Titration

I physics graduate student, but I teach an interdisciplinary lab for the university which incorporates biology, physics, and chemistry. We recently added a weak-acid titration lab to the course and I got a result which surprised me. The procedure…
Spencer
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Minimising the formation of manganese dioxide in the titration of potassium permanganate

For a titration of potassium permanganate into a standard acidified solution of hydrated iron (II) ammonium sulfate, the solution seems to end up brown (due to the formation of manganese dioxide) during the titration unless the titration is carried…
deusy
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Primary and secondary standard

Why are secondary standard solutions used in titrations? Why don't we always use primary standard solutions?
ravi
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Titration: Standardizing NaOH using PHI

Q: A student standardizes sodium hydroxide by weighing out 1.207 grams of potassium hydrogen iodate, dissolving the compound in water and titrating to a suitable endpoint: If the volume to reach the endpoint is 32.80 mL, what is the concentration of…
Kestrel
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