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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Why do universal indicators in titration have to be swirled?

Why do universal indicators in titration have to be swirled? Here's a specific example: I am using methyl orange along with hydrochloric acid to test the alkalinity of a set of household cleaners (...
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Find second acid dissociation constant at a given pH

In short, the problem states that: We have a molecule that has two ionizable groups $\mathrm{p}K_\mathrm{a,1}$ is between $5.0$ and $9.0$; $\mathrm{p}K_\mathrm{a,2}$ is outside of this range. ...
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Yellowish tinge during titration of oxalic acid with potassium permanganate

One of the our chemistry practicals involve finding the molarity of an oxalic acid solution by titrating it with standard $\ce{KMnO4}$ solution. The oxalic acid solution is heated and little sulfuric ...
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How to calculate the concentration of a monoprotic organic acid that was extracted into an ethyl ether layer?

Compound A is a monoprotic organic acid. If $25.0~\mathrm{mL}$ of a $0.456~M$ solution of A in water was extracted with $25.0~\mathrm{mL}$ of ethyl ether and it was determined experimentally that $5....
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Does titration usually always involve neutralization?

I've been doing titration exercises that involve figuring out the molarity of an unknown solution when you know the molarity of another (so like knowing the molarity of solution A but figuring out the ...
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Writing equation of reaction in stoichiometry of redox titrations

While solving some questions on the stoichiometry on redox titrations, I come across this question: Calculate the volume of $0.05\ \mathrm{M} \ \ce{KMnO4}$ solution required to oxidize completely $...
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Equivalence point of titration

Why is $\ce{[HIn] = [In-]}$ at equivalence point of a titration? I know that at equivalence point moles of known solution is equal to the moles of unknown solution, but I'm not able to relate that ...
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Is this problem about acid-base titration wrong?

I wouldn't post mere 'problems' here normally, but I will hopefully be starting to give chemistry education to some 10-11-12th graders and I want to make sure that it is not I that has a problem but ...
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390 views

pH Curves- Anomalies

In class, the other day, we were discussing pH curves. Assume that I have HCl and NaOH of concentration 1 mol/mL. Now, consider that I have 50mL of HCl, and begin adding small quantities of NaOH. I ...
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Standardization of sodium thiosulfate using potassium dichromate

In this process first we need to liberate iodine to react with sodium thiosulfate. First, sodium bicarbonate is added to a iodate-free solution of potassium iodide. The mixture is shaken until the ...
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976 views

Iodine Titration with Free SO2 in wine

To determine the free $\ce{SO2}$ in wine, a common method used is called the Ripper Titration Method. The equation is as follows: $$\ce{SO2 (aq) + I2 (aq) + 2H2O (l) -> 4H+ (aq) + SO4^2- (aq) + ...
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Regarding Kw, titrations, and pH

So I have need of performing a titration upon a fruit juice to determine acid concentration. I will be using 1M NaOH as my base. Seeing as the solution will be coloured, it would be difficult to use ...
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286 views

Do I need to include calcium chloride in this reaction equation?

Yesterday I titrated a solution of calcium hydroxide in aqueous calcium chloride with $16.7~\mathrm{mL}$ of $\ce{HCl}$. More specifically, I took $25\ \mathrm{mL}$ of the calcium hydroxide in aq ...
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Can Henderson-Hasselbalch equation be used to determine the pH of a solution when a strong base and a strong salt of that base stay together?

The following problem I have stated was not given to me as a homework. I have found this one in my textbook. I have solved it in my own way, but I'm not sure about the correctness of my procedure. I ...
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How much lactose is there in milk (mechanism)?

Iodometric titration is sometimes used to find out how much lactose there is in milk. The overall oxidation reaction is written as follows. $$\ce{C12H22O11 + I2 + 3NaOH ->[\ce{CuSO4}]C12H21O12Na + ...
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Titration of acid with base or base with acid: can I always use the same indicator?

If you are doing a titration with $\ce{NaOH}$ and $\ce{HCl}$, does it matter which one goes in the burette, and will this change the outcome of whether the solution in the beaker will turn pink due to ...
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How to determine the percentage of iron(II) and iron(III) in a solution?

Outline a plan of an experiment to determine the percentage of iron present as iron(III) in a solution containing $\ce{Fe^3+(aq)}$ and $\ce{Fe^2+(aq)}$ ions. You are provided with zinc, a standard ...
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Are titration, recrystallisation, functional group analysis, etc. outdated?

In modern chemistry, - pH meter, ion electrode, AES, HPLC, etc. replacing titration - HPLC replacing recrystallisation - IR and NMR replacing melting point analysis, derivative analysis, functional ...
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Preparing a 0.030 M solution of potassium ferrocyanide trihydrate?

I am a little bit confused on what I am supposed to do. The instructions say to prepare 250 mL of this solution by measuring out in grams the amount of PFT using a 250 mL volumetric flask. Then it ...
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How to find the concentration of an of ammonia solution by titration with nitric acid?

I am stuck with this question I am doing: To determine the ammonia ($\ce{NH3}$) concentration in a cleaning product, a chemist diluted 20 mL of the product to 500 mL. Of the 500 mL solution, 25 mL ...
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How to determine the concentration of a base through indirect titration?

$5.267~\mathrm{g}$ of $\ce{Na2CO3}$ was dissolved in $250.00\ \mathrm{mL}$ of water. $10.00\ \mathrm{mL}$ of this solution was titrated with $\ce{HCl}$. The end-point occurred at $21.30\ \mathrm{mL}$. ...
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Phenolphthalein as a indicator for the titration of benzoic acid

Question: Justify the use of phenolphthalein $(\mathrm{p}K_\ce{in}=9.4)$ as a indicator for the titration of benzoic acid $(K_\mathrm{a}=6.3\times 10^{-5})$ with $\ce{NaOH}$. My attempt: I can ...
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Strong Acid/Strong Base Titration

Bromothymol Blue is an indicator that turns yellow in acid, blue in base. If I were to titrate NaOH with HCl, what color should I look for at the equivalence point? Should I titrate until the ...
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How to read the used volume from a burette?

I conducted an acid-base titration with vinegar and sodium hydroxide today, where sodium hydroxide was used as the titrant (solution in the burette). I collected the data for the initial and final ...
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Identifying a polyprotic acid using titration

I have the following question from a high school chemistry lab: If an unknown acid has more than one equivalence point, is there a reason to expect a specific $K_\mathrm{a}$ ($K_{\mathrm{a1}}$, $K_{...
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Why isn't an Acid-base titration curve linear? [duplicate]

Sorry if this is a stupid question, but why is a acid-base titration curve not linear? As you add more acid solution to a basic solution, shouldn't the pH of the basic solution slowly go up in ...
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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:...
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Fe 2+ and MnO4- titration?

As a lab experiment, I am preparing a mixture of iron tablets dissolved in sulfuric acid so they can be titrated against $\ce{MnO4-}$. The tablet contain insoluble filler material. Why is it ...
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How to prove at what pH the color of an indicator will change based on its pKa?

The equivalence point of an acid-base titration can be determined by choosing the appropriate colored indicator. This indicator is a weak acid $\ce{HA}$. The undissociated acid has a different color ...
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Getting the wrong pH value, according to data and online calculator

I'm doing a titration problem with a week acid and strong base, I used experiment data and an online calculator to check my answer, but my pH I calculated is a bit off. Can anyone see where I messed ...
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How to calculate the pH of soft drinks based on titration data? [closed]

Your enamel is composed of a calcium hydroxyphosphate ($\ce{Ca5(PO4)3OH}$), also known as mineral apatite. This “apatite” is slowly broken down into calcium phosphate and water as illustrated in the ...
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Stoichiometry and iodometric titrations

$1.25~\mathrm g$ of a sample of bleaching powder is dissolved in $100\ \mathrm{mL}$ of water. $25\ \mathrm{mL}$ of it are treated with $\ce{KI}$ solution. The iodine so liberated required $12.5~ \...
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Why is copper(II) carbonate not selected as an unknown compound for back titration? (Whereas another unknown carbonate is used instead?)

Why is copper(II) carbonate not selected as an unknown compound for back titration? (Whereas another carbonate is used instead) I know that the carbonate to be provided on the day (not Copper (II) ...
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Shape of Weak-Strong Acid-Base Titration

I can understand why in any titration, the pH changes really quickly near the equivalent point. However, in a titration of either weak base-strong acid or weak acid-strong base, the weak acid/base ...
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Titration curve, how to find equivalence point

If you have a graphed titration curve and have points near the equivalence point like 6.85 pH at 54.60mL titrant added and 8.01 pH at 54.73mL titrant added is there any good way to find a more ...
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Calcium sulfate soluble in water

In the volumetric estimation of calcium in a given solution as calcium oxalate. We convert the calcium oxalate to oxalic acid by dissolving the former in hot (~70 °C) 2 N sulfuric acid solution. This ...
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762 views

How to determine the hydroxide ion concentration in an acidic aqueous solution?

When doing a titration with $\ce{HCl}$ and $\ce{NaOH}$, both being strong and dissociating completely, if you add a volume of $\ce{NaOH}$ that is less than needed to reach the equivalence point, you ...
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Buffer formation in weak acid/strong base titration?

I'm a little confused about what happens when you titrate a weak acid or base. For example, let's say that you are trying to titrate a weak acid. Based on this question, it seems like the weak acid ...
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Titration curve graph, finding exact point of the equivalence point

I plotted all my data points and made this graph in excel. Now I need to find the volume of titrant required to read the equivalence point, as well as the pH after 18.5 mL of titrant have been added. ...
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Making a 10L HCl solution with 8.77% HCl in a 100 mL solution from a 16 M stock solution

How would you make 10L of HCl solution with 8.77% HCl in 100 mL from a 16M stock solution. Here's what I have tried so far: I put my percent HCl and got that down to match with the moles of HCl I ...
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Which method can be used to determine the pKa of an acid-base indicator like bromothymol blue?

I have a question about how one would determine the pKa of an acid-base indicator such as bromothymol blue. I know that spectrophotometric analysis is one option, but is it possible to perform an ...
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Concentration of a species outside buffer region (polyprotic acid titration)

I'm wondering if you titrate a polyprotic acid, say, $\ce{H3PO4}$, with a strong base, and you successfully pass the first equivalence point and are maybe at the $\mathrm{pH}=\mathrm{pK}_{a2}$ point ...
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Why does more acetic acid require more sodium hydroxide in order to be neutralized

I was recently titrating sodium hydroxide against vinegar and based off my results i realised that the vinegars with a higher concentration of acetic acid required more sodium hydroxide in order to ...
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Why is silver nitrate used for cyanide titration?

Or more to the point, since silver isn't exactly cheap: Why can't cuprous nitrate ($\ce{CuNO3}$) substitute for the pricier ($\ce{AgNO3}$) in cyanide titration? I assume that free cyanides bind ...
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What concentration (M) of citric acid should I use in a titration with 0.02M LiOH?

I am using an automatic titrator that records the amount of acid/base added and the pH of the solution in the form of a graph. I am trying to titrate citric acid to capture all 3 pKas in this graph. I ...
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Precipitation of Calcium ions in basic Sodium Hydroxide solution?

I recently conducted an EDTA titration of milk to find its Calcium contents. I got a value significantly smaller than the theoretical value. (≈10 times smaller). I made $50ml$ samples to which I added ...
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Concentration of NaIO3 using hypo

$$\ce{2NaIO3 + 5NaHSO3 -> 3NaHSO4 + H2O + I2 + Na2SO4}$$ $\mathrm{20ml}$ of $\ce{NaIO3}$ solution reacted with excess $\ce{NaHSO3}$ releasing $\ce{I2}$ that can oxidize $\mathrm{20ml}$ of $\...
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Neutralization equation [closed]

If I have cider vinegar and want to calculate the total moles of acid found in it, how can I do it? I have the moles of NaOH and I know that it includes both acetic and malic acid but how can I ...
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How do I get the molarity of solution 1 given volume 1, molarity 2, and volume 2? [closed]

For example: What is the molarity of a $\ce{NaOH}$ solution if $25\rm~mL$ of the solution is exactly neutralized by $44\rm~mL$ of $0.32\rm~M~HCl$? I know that the abstract function is $$\text{...
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Is this asking for the equivalence point?

Is this question asking for the equivalence point of the titration curve? At what point does the concentration of acetic acid equal the concentration of the acetate ion? What is the pH of the ...