Redox titration Puns

Vitamin C is a vital component of a healthy diet which is why, like many others, my father takes vitamin C supplements. However, I noticed that the vitamin C tablets he takes expired in.

Can somebody explain ciii pls?

Yeah, I'm pretty proud of myself. I've been the top student of chem 1/2 this entire year and I really didn't expect myself to do this well. I'm just really happy right now :)

idk if this is the right spot to post something like this i have never used reddit.

i am being tasked with comparing the accuracy of redox titration and thermal decomposition when determining the molecular formula of a hydrated salt. however i haven't learned anything about redox titration or thermal decomposition so the lab involves a lot of research. are there high school student accessible salts that can undergo both processes and could someone recommend one? or perhaps give insight into determining what makes a good hydrated salt for each and then maybe i can pick the best salt. i apologize if my question doesn't make sense, i began my research today and am basing my question off of my initial thoughts of the lab! thx :D

honestly if someone can just explain the key differences between thermal decomposition and redox titration that would be so helpful

Hi, part of my chemistry assessment is analysing the effect light (UV-A) will have on vitamin C (ascorbic acid) in fruit juice (lemon juice). The concentrations will be analysed through titration between the juice and iodine in a redox reaction. Does anyone know the process of how UV light will effect the concentration, assuming we know that its concentration will decrease?

If UV light can cause the persistence of ascorbyl free radicals, does anyone also know how it can link to oxidative enzyme activity (if there is a link) as this is known to influence the degradation of Vitamin C.

I need a bit of help with my chemistry ia. The thing is that I cannot find data for my chemistry IA. Im doing concentrations of vitamin C at different temperatures in oranges/ orange juice and I could only find 1 work I can cite, but i need 2 more, if anyone has any sources I could use pls share id appreciate that a ton

Apologies for my lack of knowledge — I’m a high school student, but my teacher hasn’t been of much help and lab time is limited because of COVID-19. I’m doing an experiment on the effect of temperature on oxalate leaching from beetroot. To do this I’d put a certain mass of beetroot into a test tube with water, immerse it into a water bath set at different temperature intervals for some amount of time, take a sample of the test tube water, and use a KMnO4 redox titration to determine the oxalate content of the water and therefore how much oxalate is leached from the beetroot. I’ve also read that since KMnO4 is autocatalyzing, I need to heat the oxalate solution to 80°C and then titrate it (McBride method).

However, I saw in another thread with a similar experiment involving spinach said it would be very time-consuming and difficult at the high school level. Is this still true with beetroot? And are there any modifications to this experiment that might make it more viable at a high school level? I might use EDTA to look for calcium/magnesium leaching instead in spinach, but I’m not sure how I’d differentiate between the 2 in the solution.

Any advice is appreciated!

Planning a general chemistry lab with commercial bleach, KI, a strong acid, sodium thiosulfate, and starch indicator.

Theoretically, we'd add molybdate (like ammonium molybdate) as the initial indicator to bleach. Then, once the brown color turns more yellow, we add starch as the indicator to more clearly visualize the endpoint. The titrant is the sodium thiosulfate.

We don't have a lot of stock in our lab space - would this titration work fine without molybdate?

Thanks all!!

Alright chemistry brains.

I'm teaching high school chemistry and I'm trying to renew myself and my material. I'm looking for a redox titration for my students. I'm tired of the usual permanganate titrations, and I think ascorbic acid is too difficult.

Any suggestions? Preferably determination of something everyday / real world.

I'm currently doing a lab report on redox titrations, but I don't know how to explain why a colour change occurs.

In a redox titration, why does a colour change occur in the unknown solution? Is it the result of a pH change? If not, why does the solution change colours?

I understand that the colour change indicates that the titration has reached the endpoint, but I don't know *why* the colour change occurs.

Question 5: https://imgur.com/a/Qq1PIfO

I balanced the reaction as: MnO4^- + 8H^+ + 5Fe^2+ -> 5 Fe^3+ + Mn^2+ + 4H20

I converted the volume of 6.85 ml to 0.00685L.

mols of KMnO4 = 0.00685 L * 0.150 mol/L

= 0.00103 mol

mols of Fe = 0.00103 mol KMnO4 * 5 mol Fe/1 mol KMnO4

= 0.00514 mol Fe

mass Fe = 0.00514 mol Fe * 55.85 g/mol

= 0.287g * 1000mg/g

= 287mg

V of aliquot = 25 ml = 0.025L

So the amount of iron = 287mg/0.025L

= 11,480 ppm

Do you think this is correct? Am I missing something?

I have two problems that I don't understand how to do:

1. The iron content of iron ore can be determined by the titration with standard KMnO4 solution. The iron ore is dissolved in HCl and all the iron is reduced to Fe^2+ ions. The solution is then titrated with KMnO4 solution, producing Fe^3+ and Mn^2+ ions in acidic solution. If it required 41.95 mL of 0.0205M KMnO4 to titrate a solution made from 0.6128 g of iron ore, what is the percent (by mass) of iron in the iron ore?
   1. Given this equation: 5Fe^2+ + MnO4^1- + 8H^+ = 5Fe^3+ + Mn^2+ + 4H2O
2. The quantity of antimony in a sample can be determined by a redox titration with an oxidizing agent. A 7.70 g sample of stibnite, an ore of antimony, is dissolved in hot, concentrated HCl and passed over a reducing agent so that all the antimony is in the form Sb^3+ . The Sb^3+ is completely oxidized by 43.7 mL of a 0.125M solution of KBrO3. The balanced equation is: BrO3^1- + 6H^1+ + 3Sb^3+ = Br^1- + 3Sb^5+ + 3H2O
   1. Calculate the amount of antimony in grams in the sample and its percentage in this ore.

Thanks in advance!

So, my chemistry IA is looking less and less optimistic, I've re-written it almost 5 times and it hasn't gotten a score in the double digits... It's been hard to know how to improve since I haven't been able to find anyone who has done or is currently doing the same question as I am. I'd appreciate any help if you can!

Question ————— A student weighed 5.95g of an unknown copper(II) salt and dissolved it in distilled water. This solution was added to a 250cm3 volumetric flask and was made up to the mark with distilled water. 25.0cm3 of the solution was transferred into a conical flask and 10cm3 of potassium iodide (an excess) was added. The copper(II) ions reacts with iodide ions, I-. The resulting solution was titrated against 0.100 moldm-3 sodium thiosulphate and 24.05 cm3 of sodium thiosulphate was used. Calculate the molar mass of the copper(II) salt.

—— Answer: 247gmol-1 The answer is achieved by using the same number of moles of Cu^2+ as S2O3^2- and using the dilution factor of 250/25 which is the part in which i don’t understand as according to my balanced equation, it’s a 1:2 ratio, not to mention that theres an additional 10cm^3 (of KI) which I don’t know what to do with and why it’s ignored ————————— My position in solving the question:

Using the balanced redox equation: Cu^2+I2 + 2S2O4 -> 2S4O6^2- +2CuI no idea what to do with the 10cm^3 KI Firstly I find the number of moles of S2O3^2- by 0.02405dm^3 X 0.1M =2.405x10^-3mol. From here on, I ignored the I^- in KI but did take note of the additional 10cm^-3, which are both wrong. This being that I don’t think it is significant and because I have no idea how to balance the equation with another set of stuff involved or what KI reacts with/forms. Please tell me where I went south and how I should correct this

Does it come under amount of substances like the sodium thiosulfate questions and stuff

Made 0.0005M dcpip with 0.0005M ascorbic acid and can not get to standardise as colour stays pink and does not go colourless in presence of ascorbic acid std... we are old school burettes and no spectro to check colour change so need clear end point. Help anyone please?

A fraction of 25ml of a sample containing Fe(II) and Fe(III) reaches the final point in a titration with Ce(IV) 0.1234 mol/L after adding 17.86 mL of the titrant. A second fraction of 25 mL of the same original sample goes through a reduction process and, afer titration consumes 22,54 mL of the cerium solution. What are the concentrations of Fe(II) and Fe(III) on the sample?

Hey guys I'm having a problem with this question mostly in finding Fe(III) concentration, I used Mv=Mv to find a Fe(II) concentration of 0.08816M with the data given, and matches the answer sheet. Is this right or it was a lucky shot? How can I find the Fe(III) concentration?

Thanks!

Hi guys,

I was going through the Kaplan books for content and the idea of a redox titration came up. I understand acid-base titrations, but can someone explain this concept to me? Should I even focus on it?

Thanks in advance!

For reference, I will be titrating with a 0.005M iodine solution and using 0.25% starch solution as the indicator. The end product will be a mixture of orange juice and the iodine-starch complex.

I know that I2 itself is extremely toxic to the environment/marine life and has special disposal procedures but if it’s in the form of a complex with starch how would it be disposed of? Would it be safe to pour down the drain?

Vitamin C is a vital component of a healthy diet which is why, like many others, my father takes vitamin C supplements. However, I noticed that the vitamin C tablets he takes expired in.