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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4
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3answers
193 views

Is pK_{In} = pH at equivalence point still true for weak basic organic indicators?

I am reading Ostwald Theory of Titration which says that indicators are organic weak acids or bases. To prove the relation that $\mathrm{p}K_\mathrm{In} = \mathrm{pH}$, the textbook uses the following ...
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1answer
196 views

How to determine the purity of lactic acid with titration?

$\pu{25 mL}$ of $\pu{0.5 \%(w/v)}$ lactic acid ($\ce{C3H6O3}$, molecular mass $\pu{90.1 g mol-1}$, $\mathrm{p}K_{\mathrm{a}} = 3.86$ was neutralised by $\pu{13.1 mL}$ of $\pu{0.1010 M}$ monobasic base....
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1answer
89 views

Can the titrant and the unknown material be flipped?

We know the typical experiment of determining the concentration of $\ce{Fe^2+}$, where we titrate $\ce{MnO4^-}$ which has dark purple color and watch the color of the bottle. Can we also determine ...
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2answers
98 views

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 ...
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2answers
137 views

How come we can't use the equivalence point equation of NV=NV in this problem?

So, the problem is you prepare to standardize a $\ce{Na2S2O3}$ solution. $\pu{32 mL}$ of $\ce{Na2S2O3}$ solution is titrated into $\pu{50 mL}$ of a $\pu{0.01 M} \ \ce{KIO3}$ solution to reach the ...
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1answer
4k views

Finding the pH among HF and KOH

Okay I ran into this question in homework. A 100.0 ml sample of 0.20M HF is titrated with 0.10 M KOH. Determine the pH of the solution after adding 200 ml of KOH. The Ka of HF is 3.5 x 10-4? Oh yeah ...
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41 views

Drying sodium tetraborate for use as a standard

I am currently attempting to purify technical grade sodium tetraborate decahydrate by recrystallization for use as a titration standard. I don't have a requirement for a specific grade or purity. I'm ...
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1answer
168 views

Confusion about Titration Formula [closed]

When performing a titration of a monoprotic acid and a monoprotic base, water can not be added to the titrant but water can be added to the analyte. To prove this statement to myself, I decided to ...
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3answers
298 views

Volume calculation perchloric acid 70%

HClO4= 100.5, d HClO4=1.8, (ACO)2O=102, d (ACO)2O=1.1, H2O=18, d H2O=1 A) Preparation of 100 ml perchloric acid 0.1 Molar aqueous solution. below is my answer, but what I'm not sure is that the ...
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2answers
2k views

What is the difference between Half Equivalence point and Equivalence point?

OKay I learned in class that equivalence point is the time of neutralization, where the # of moles of acids and base present is in equivalence/same amount. Now I was also told that Half equivalence ...
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1answer
52 views

Will increasing temperature have an effect to the pH of honey to be able to carry out an acid-base titration? [closed]

After doing some research on how to decrease the viscosity of honey to undergo acid-base titration with NaOH, one of the ways was by increasing the temperature of honey but the problem is that the pH ...
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2answers
185 views

Titrating iodine starch solution with sodium thiosulphate - Colour change

I investigated two mixtures with different solvents, one with water and one with n-heptane. Both contained iodine $\ce{I2}$ as a solute. To both solutions I added a bit of starch. As I remember this ...
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1answer
56 views

Finding the volume needed to make a new pH

In the titration of 20.00 mL of 0.500 M HCl by 0.500 M NaOH, calculate the volume of 0.500 M NaOH required to reach a pH of 2.0. I have tried to change the 20.00 mL into the amount of substance (0.01 ...
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0answers
727 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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Why is the experimental pH of vinegar (acetic acid) so much higher than expected?

I bought some sodium hydroxide on Amazon and went about titrating solutions I make with it. As I'm an amateur chemist at home, I have limited tools. A pad of paper, some 5% acetic acid vinegar, and ...
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1answer
347 views

Indicator error in acid-base titration [closed]

If we value a 20 mL solution of 0.25 M acetic acid with a 0.1M solution of NaOH The end point of the titration is reached when 50 mL of NaOH is added from the burette. At this point, the pH of the ...
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1answer
16 views

Heterogeneous ion solution

I am a college student and for my chemistry of solutions class, I had a lab where we had to titrate orange juice to check the calcium content. However, the experimental results are 20% off the ...
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1answer
31 views

Different products using different indicators

A question states that 0.1 M solution of compound$$\ce{Na2CO3.NaHCO3.2H2O}$$ is titrated against 0.05M HCL, and that a different amount of HCL is used according to the indicators(phenolphthalein or ...
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1answer
50 views

Can I use an acid other than sulfuric for hydrogen peroxide determination?

I would like to perform a permanganometric titration of hydrogen peroxide at home following a procedure similar to http://www.titrations.info/permanganate-titration-hydrogen-peroxide, i.e. the ...
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1answer
30 views

How concentrated does the analyte solution need to be in order to perform a (chelatometric) titration

I’m currently investigating a method to chemically pretreat cellulosic waste as bisorbents for enhanced uptake of lead in water. I intend to measure the initial and final concentration of water to ...
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3answers
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How would a pH curve look like for titration of diluted weak base compared to concentrated one?

Let's say I take $\pu{80 g}$ of a weak base, dilute it with $\pu{50 ml}$ of water and titrate it with a strong acid. I get a titration curve. Now I take again $\pu{80 g}$ of the same weak base but ...
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1answer
1k views

Differentiating between Titration, Buffer, diluted buffer, Deionized H₂O

I had a chemistry lab where we had to titrate three solutions with $\ce{HCl}$: a buffer, a diluted buffer and deionized water. My partner and I didn't label the charts we made, so now I have to figure ...
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1answer
109 views

Why does a strong base completely neutralize a weak acid? [closed]

For the longest time, weak acid-strong base titration curves completely baffled me. I understood that the equivalence point of a strong acid-strong base titration is reached when equal numbers of ...
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1answer
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172 views

Why does the concentration of the acid equals that of the base at the mid-point of titration? [closed]

Consider this graph of the titration of a weak acid and a strong base: The buffering region is strongest at the midpoint of titration because there is equal concentrations of acetic acid and its ...
5
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1answer
558 views

Back titration of excess HCl used for dissolving limestone

$15.0~\mathrm{mL}$ of $1.4~\mathrm{M}\ \ce{HCl}$ was mixed with $1.00~\mathrm{g}$ of limestone (impure $\ce{CaCO3}$) until all the solid had dissolved. The solution was then transferred to a conical ...
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1answer
46 views

Measure ethanol volume fraction in a beverage [closed]

Given a sample of an alcoholic beverage (be it beer, wine, etc..), what are possible methods to find out the ABV (alcohol by volume) of it with moderate accuracy? As fas as I know, some methods exist ...
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1answer
53 views

Estimation of Sodium Hydroxide

Why is estimation of sodium hydroxide more accurate with oxalic acid rather than with sulfuric acid or any other strong acid?
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8k views

How to determine the iron content in spinach from a titration with permanganate solution?

I used titration to find the mass of iron in a $5~\mathrm{g}$ sample of spinach after leaving the spinach to soak in tap water for 5 different amount of times. I added $\ce{H2SO4}$ to the solution and ...
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2answers
2k views

How does an acid prevents or discourges oxidation of iron?

In the titration of $\ce{KMnO4}$ with Mohr's salt, I have learned that sulphuric acid prevents oxidation of $\ce{Fe^2+}$ to $\ce{Fe^3+}$ in the solution before the actual titration. How does the acid ...
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56 views

Iodometric Titration: Would iodine react with sucrose as well?

I'm currently planning to do a lab experiment about the effect of sugar addition (sucrose) to orange juice on Vitamin C (ascorbic acid), also finding the degradation rate and activation energy ...
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1answer
503 views

Why is high molar molar mass a requirement of good primary standards for volumetric analysis? [closed]

I have been taught that using primary standards with a relatively high molar mass will reduce the error between the equivalence point and the end point during titration. However, I am unsure as to why ...
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1answer
281 views

Can sodium carbonate-sodium bicarbonate buffer be used for EDTA titration of calcium?

I am planning to measure general/total hardness (calcium and magnesium) of aquarium water using EDTA titration with Eriochrome Black T indicator. From what I understand, the unknown solution must be ...
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1answer
1k views

What is the relation between volume strength and normality of H2O2? [closed]

I have been told that: $$\text{equivalent weight of }\ce{H2O2} =\text{molecular weight of } \ce{H2O2}$$ as it's $n$-factor is $1$ (from balanced equation). But in my book it's given that: Molarity $=...
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1answer
366 views

What is the role of various additives in a titration of vitamin C with N-bromosuccinimide

In a titration to determine the amount of vitamin C in an orange juice sample, the following were mixed with water: oxalic acid potassium iodide starch acetic acid Then, the mixture was titrated ...
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3answers
244 views

I have a solution of citric acid, tartaric acid, water and glucose. How do I find the concentration of the citric acid present in the solution?

If I try to find the concentration of citric acid through back titration or reverse titration, the base I would use, like NaOH, would react with both acids to form sodium citrate and sodium tartrate, ...
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1answer
198 views

Is chromate a suitable indicator for the titration of Ag⁺ with Cl⁻?

To titrate $\ce{Cl-}$ with $\ce{Ag+}$ we use chromate $\ce{CrO4^2-}$ as an indicator. The titration reaction is: $$\ce{Ag+ + Cl- <=> AgCl}\tag{R1}$$ $$K_1 = \frac{1}{K_\mathrm{sp}(\ce{AgCl})} =...
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2answers
10k views

Titration of H2SO4 w NaOH: Solving for the molarity of H2SO4?

I am given $\ce{H2SO4}$ in a reaction vessel of about $50~\mathrm{mL}$. I need to solve for the molarity of $\ce{H2SO4}$. A $10~\mathrm{mL}$ sample of $\ce{H2SO4}$ is removed and then titrated with $...
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1answer
2k views

Equivalence point vs inflection point in the titration curve of a weak acid

Let's suppose we want to titrate a solution containing an unknown monoprotic and weak acid. We use a strong base, such as $\ce{NaOH}$. When the number (and moles) of hydroxide ions coming directly ...
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1answer
425 views

Phenolphthalein and methyl orange end points comparison [closed]

In determining the solubility constant for Ca(OH)2, how does phenolphthalein end point compare with the methyl orange end points?
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277 views

How can you use indicator titration to determine the pH of a complex solution like ocean water if at all

Could you measure the pH of ocean water by using a strong acid-weak base titration? I was thinking that you could set up a standard titration with ocean water as the "unknown", and drip the known HCl ...
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1answer
161 views

Acid-base titration: Unknown base in burette or flask?

While finding the concentration of $\ce{NaOH}$ via titration with $\pu{0.05M}$ Oxalic acid solution (in our lab) we put NaOH in the burette whereas added phenolphthalein to oxalic acid in titration ...
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1answer
235 views

When disolving a iron pill for titration, why do I use sulfuric acid instead of nitric or hydrochloric acid?

In a titration to decide the iron content of a pill we dissolved the iron in sulfuric acid and then titrated it with cerium(IV) sulfate. But I just wondered what's wrong with using nitric and ...
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1answer
83 views

Winkler's method in the absence of iodide

I'm currently doing an IB chemistry individual investigation on the effect of adding bleach to water on the water's dissolved oxygen content. I've used Winkler's method for this and I'm just wondering ...
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3answers
47k views

Volume required to dilute solution for a pH change

A $\pu{100 mL}$ solution of $\ce{NaOH}$ has a $\mathrm{pH}$ of $13$. What volume of water in $\pu{mL}$ must be added to change the $\mathrm{pH}$ to $11$? My steps: Begin by calculating conc. of $[\...
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0answers
45 views

Factors affecting hardness of water - EDTA titration

I am thinking of doing a project involving EDTA complexometric titration to determine the hardness of the water. I am not sure if the pH will affect the hardness of the water. If it did, I would ...
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1answer
317 views

Titration/ Separating Soluble Salts/ NaHSO4

When performing titration between NaOH and H2SO4, both Na2SO4 and NaHSO4 are formed (both are soluble in water), is there any method to obtain crystals of NaHSO4? (Maybe by separating two soluble ...
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0answers
84 views

Calculating the solubility of aspirin in water

I am trying to investigate the relationship between the solubility of aspirin in water with the relationship to some variables. In my investigation, I seem to be stuck with the calculation of finding ...
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1answer
72 views

Why do strong polyprotic acids not dissociate completely, whereas strong bases with multiple (OH)- groups do?

$\ce{H2SO4}$ is a strong acid, which follows the reaction $$\ce{H2SO4 -> HSO4- + H+}$$ Not $$\ce{H2SO4 -> SO4^2- + 2 H+}$$ However, $$\ce{Ba(OH)2 -> Ba^2+ + 2OH-}$$ Is there a reason why ...
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1answer
658 views

Redox Titration in investigating change of Iron in Avocado [closed]

I'm trying to investigate the change in iron in an avocado as it ripens. I'm planning on using redox titration but still a bit unsure of how to carry out the investigation (method). Do you have any ...

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