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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754 views

How can a conductivity meter be used to determine the equivalence point?

I know how a conductivity meter works. Power is supplied to electrodes and these electrodes change charge. The ions in the solution will be attracted to the oppositely charged electrode. The charge ...
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371 views

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 ...
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When titrating a weak acid should only undissociated acid molecules be considered?

Let's say we do the titration of a weak acid (acetic acid in this case) and a strong base (sodium hydroxide) represented by the following equation: $$\ce{CH3COOH + NaOH -> CH3COONa + H2O}$$ My ...
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442 views

Hardness of water using EDTA calculation issue

I have been asked to work out the hardness of water in German degrees and this is what I did: I got a sample of water I didn’t measure how much I put into my volumetric flask perhaps it was $\pu{8....
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73 views

Replacement for Centrifuge in Calcium Content Determination

Basically, I'm performing a lab investigation to determine calcium content in different milk sorts. Since my school didn't have any EDTA, I'm using Sodium Oxalate to form a precipitate with Calcium ...
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115 views

Is it possible to calculated the concentration of hydroxide ions from the known concentration of hydronium ions?

I came across the following question in Chapter 15 (Acids and Bases) of Holt High School Chemistry: Neutralizing $\pu{5.00 L}$ of an acid rain sample required $\pu{11.3 mL}$ of $\pu{0.0102 M}\ \ce{...
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6k views

Titration with Ca(OH)2

In the laboratory, $20.0$ milliliters of an aqueous solution of calcium hydroxide, $\ce{Ca(OH)2}$, was used in a titration. A drop of phenolphthalein was added to it to indicate the end point. The ...
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836 views

Questions on concentration [closed]

Currently I am attempting two questions on concentration but I am not sure if I am correct. Can someone help me with these questions? These are the questions: 1) Calculate the volume of pure water ...
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Determining the calcium content in cashews via titration?

I have been planning on an experiment for quite some time now (as part of my after-school chemistry club), but I still feel like I am missing something. Due to my family's calcium deficiency, I ...
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2k views

What source of error in an acid-base titration could lead to a higher reading of the acid concentration?

Methanoic acid ($\ce{HCOOH}$) is found in stinging nettles. In an analysis of the concentration of methanoic acid in a solution extracted from nettles, the solution was titrated with a standard ...
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796 views

What is the role of the sulfuric acid in a titration between potassium permaganate and iron ammonium sulphate solution?

So basically my titration was of finding the concentration of potassium permaganate against an iron ammonium solution. In the iron ammonium sulphate solution it consisted of water, iron ammonium ...
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Titration homework question

My friend sent me this for his homework, and I haven't done a titration calculation in years. A student titrated $\pu{10.00 mL}$ aliquots of her unknown amino acid solution with standard $\pu{0....
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Could An Equivalence Point Be Calculated or Deduced Based on Limited Data with Accuracy?

I have recently been tackling a problem from one of my A-Level chemistry exercises on the topic of acids and bases, particularly with strong base and weak acid titration curves: A titration is ...
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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 ...
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37 views

Concentration of acid when titration has reached equivalence point? [duplicate]

I'm currently working with a lab report concerning titration. One of the tasks is to calculate the concentration of the weak acid ($\ce{HOAc}$) and the strong acid ($\ce{HCl}$) at the equivalence ...
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109 views

Why isn't there a third buffering zone in the pH curve of this titration?

I'm in chem 30 right now and we were learning about pH curves and buffering zones. I was looking at a question on the titration of $\ce{H3PO4}$ with $\ce{NaOH}$. The curve showed two qualitative ...
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691 views

Saponification Value of a fat/oil

The saponification value of a fat was determined by adding $\pu{9.0 g}$ of the fat to flask containing $\pu{50.0 cm3}$ of $\pu{1.00 M}$ ethanolic potassium hydroxide. The remaining solution was ...
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1answer
749 views

Can titrant and analyte be swapped?

I just did a titration experiment at school, our teacher told us multiple times to add the solution of known concentration into the solution of unknown concentration. I am wondering if we can do it ...
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What is causing the buffer region in a weak acid - strong base titration?

For the buffer region in this, why does it stop the pH from increasing? At the start: $$\ce{CH3COOH + NaOH -> CH3COONa + H2O}$$ Which means there will be a high amount of salt in the solution, ...
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948 views

How do I determine which is the reduction reaction in a hydrogen peroxide and potassium permanganate solution?

How was it determined that $\ce{MnO4-}$ was reduction, and $\ce{H2O2}$ was oxidation? Also, why wasn’t the equation $$\ce{MnO4- + 2H2O + 3e- -> MnO2 +4OH-}$$ used? Or the $$\ce{H2O2 + 2H+ +2e- -&...
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707 views

How to correctly prepare a standard solution?

Having just spoken to my teacher about the creation of a standard solution, and she suggested one way of doing it, however a previous chemistry teacher had told us a different way of doing it. My ...
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67 views

Is this enough information to solve this problem?

Calculate the volume of a $\pu{0.100M}$ solution of $\ce{HNO2}$ and the volume of a $\pu{0.200M}$ solution of $\ce{NaNO2}$, that must be mixed to prepare $\pu{300ml}$ of a solution with a $\mathrm{pH=...
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How is the the law of chemical equivalence defined and what are its limitations?

I've heard that the law of chemical equivalence states that the gram equivalence of each of the reactants equals the gram equivalence of each of the products. But I'm facing difficulties in ...
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1answer
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In a mixture of NaOH and Na2CO3, why doesn't phenolpthalein change its color until Na2CO3 is half neutralised?

Let us consider a mixture of $\ce{NaOH}$ and $\ce{Na2CO3}$. Based on what I have understood, double titration works in the below manner : Phenolpthalein turns pink when added to the mixture. As $\...
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1answer
316 views

Titration - Just need your judgement

A student investigated the volume of sulfuric acid that reacted with 25 cm3 sodium hydroxide. Describe a titration method the student could use in this investigation. {6 marks} My answer: Use the ...
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263 views

Does changing EDTA concentrations affect the amount of calcium ions in milk?

For my chemistry experiment I am titrating EDTA against milk to find out the concentration of calcium ions in milk. I will be using EriochromeT as the indicator. The lab tech said that if I use ...
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127 views

Formula for finding how much base to add to buffer to obtain a desired pH

Given: molarity and volume of the weak acid, molarity of the strong base, desired $\ce{pH}$, $K_{a}$ of the acid. I tried coming up with a formula to solve for the amount of base to add in order to ...
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1answer
368 views

How can the standard deviation for a set of experimental value be interpreted in terms of precision?

I have read from many websites that the sample standard deviation can be used to measure the precision of experimental values. I understand that the lower the standard deviation the better, as it ...
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Why titrating strong base with weak acid doesn't end at pH 7? [duplicate]

If I understand this titration correctly, if we titrated 50mL 1.00M acetic acid with 1.00M NaOH, the equivalence point would happen at a pH greater than 7, and less than 50mL of NaOH would need to be ...
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995 views

How to Prepare a 80mL Carbonic Acid-Bicarbonate buffer solution of ph=7.4 in laboratory? [closed]

I have the following materials which I can use: 0.1 M sodium bicarbonate solution Sodium Bicarbonate powder 0.1 M HCL Distilled Water Universal Indicator It will be a great help if you can provide ...
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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 ...
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Why does a titration have to be precise?

When we do titrations (w/ phenolphthalein) in lab, I know it's fun to see how close we can get the solution to clear, but why does my teacher place so much emphasis on accuracy and criticize ...
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1answer
834 views

Is the amount of substance of acid and base always equal at the equivalence point?

Does the amount of substance of acid always have to equal the amount of substance of base at the equivalence point? I know it "works" for monoprotic acids and monobasic bases, but what if we had a ...
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760 views

Redox Titrations Half & Full Equations

I was presented with the following problem and I am finding it difficult to present the half equations for the answers. I managed to produce the half-equation for the Iodine redox. $\ce{2I- -> ...
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A titration mixture having pottasium oxalate and pottasium hydrogen oxalate!

I came across this question, this is how it goes- A solution is prepared by dissolving a solid mixture of $\ce{K2C2O4}$ and $\ce{KHC2O4}$. A $\pu{10 ml}$ portion of this solution required $\pu{10 ml, ...
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Calculating the pH of soft drink [closed]

Me and my classmates are doing an experiment in order to determine the pH of Sprite. We are going to conduct a titration with NaOH. We are taking under consideration that the citric acid in Sprite is ...
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1answer
111 views

How to find pH in the following titration/buffer problem given concentration of base and acid

A $100. \text{ mL}$ sample of $0.10 \text{M } \ce{HCl}$ is mixed with $50. \text{ mL of } 0.11 \text{M } \ce{NH3}$. What is the resulting pH? (Kb for $\ce{NH3} = 1.8 × 10–5$) I was thinking more ...
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How to determine which combination of substances will give a buffered solution given target pH and Kb of each substances

What combination of substances will give a buffered solution that has a pH of 5.05? (Assume each pair of substances is dissolved in 5.0 L of water.) (Kb for NH3 = $1.8 × 10^{–5}$; Kb for C5H5N = $1.7 ×...
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How to solve titration problem?

A sample of 40.0 mL of a .100 molar HIO solution is titrated with a .150 molar NaOH solution. Ka for hypoiodous acid = 2.3 x ^ (-11) What is the pH of the solution? I have the following work: As you ...
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Why is a titration necessary? Why can't we just compare the moles of the acid and base?

For the following question: $\mathrm{1g}$ of $\ce{Mg(OH)2}$ is completely dissolved in $\mathrm{25}$ mL of $\mathrm{0.5}$ M $\ce{HCl}$. This solution is then titrated with $\mathrm{0.1}$ M $\ce{NaOH}...
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Dichromate-thio titration

Can dichromate in acidic media be titrated directly with buffered thiosulfate solution using $\ce{H2O2}$ as an external indicator instead of using $\ce{KI}$ which is a standard procedure? $\ce{...
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323 views

How would one correct for a blank in a potentiometric titration?

I want to do a potentiometric titration with perchloric acid of a sample consisting of active drug (weak base) and two other components. Based on theory, I already know that these two other components ...
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How to determine the theoretical concentration of the acetic acid solution in mol dm-3 of vinegar

How do you determine the theoretical concentration of an acetic acid solution in mol dm-3 of vinegar that is 5% acetic acid, knowing that the density of vinegar is 1.000g cm-3?
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How do I find the moles of NaOH required to reach the equivalence point? [closed]

For each trial with the unknown acid, calculate the following: a) Moles of $\ce{NaOH}$ required to reach the equivalence point. I need help with part A. I have already solved and figured out the ...
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274 views

Diprotic Basic Buffer

So, as part of an experiment, I plan to make a diprotic basic buffer. For a monoprotic basic buffer, I used the standard combination of Ammonia and Ammonium Chloride. However, how can I make a ...
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Color change of potassium permanganate during a titration with Fe(II)

Is it possible for potassium permanganate to have color change (in a titration) from colorless to pink? If so, then in what circumstances (particularly for a titration)? I have been always been taught ...
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Titration of caffeine using Iodine

I was trying to do an investigation on the variation of caffeine content with temperature. I used 6 Lipton yellow label tea bags (black tea) to brew the tea solution. Next, I perform the extraction of ...
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Why, in titration, is universal indicator not commonly used?

My teacher said that we always used indicators such as methyl red, methyl orange, litmus, phenolphthalein, etc. rather than universal indicator. I don't understand why, though, would not universal ...
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Relating pH and buffer capacity

So, here is the equation for a weak acid - strong base pH curve And here is the expression gotten when the derivative of concentration of hydronium ions with respect to volume of base added is ...
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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, ...