Sulfuric Acids - Science topic

Hi all,

I am running an experiment using sulfuric acid and would like to capture the amount of sulfuric acid in the system using micro-CT images. I want to ask if anyone knows what sort of highly dense component can be mixed with sulfuric acid to add up the contrast under micro-CT images without chemical reactions.

Thank you!

I need to purify and then functionalize the carbon nanotube to improve its properties. The functional group that I want to add to the carbon nanotube is carboxylic acid (COOH).

I would like to know how to purify and functionalize carbon nanotubes using a mixture of nitric acid (HNO₃) and sulfuric acid (H₂SO₄).

The information I need in this case includes the following:

The best and most accurate method to add COOH functional group to carbon nanotube?

The amount of used carbon nanotubes?

The quantity and amount of used acids?

The ratio of acids together?

The best time is to mix the carbon nanotube with the used acids?

The best temperature to get the best result?

The exact way to wash to achieve a neutral pH?

And the optimal temperature and time for drying?

If you could help me, I'd really appreciate it.

Subject: Seeking Expert Advice on Suitable Electrolyte Solution and Voltage Parameters for Pure Aluminum Electropolishing Study

Dear Research Community,

I hope this message finds you well. I am a student facing a critical issue that could potentially jeopardize my future. I am reaching out to seek your assistance or recommendations for someone who can help me overcome this challenge.

Currently, our research project focuses on the electropolishing of pure aluminum. However, we have encountered a significant obstacle that has impeded our progress. Our samples vary in size, with the maximum dimension being 0.5 cm.

In our study, we initially prepared the samples through sanding and subsequent polishing with powder. We have now reached the stage where we are ready to initiate the electropolishing process.

For the electrolyte solution, we have utilized a mixture of acids, including nitric acid, sulfuric acid, acetic acid, and ethanol. Initially, we created an electrolyte solution consisting of 25% nitric acid and 75% ethanol. The process was conducted at room temperature without employing a heater to raise the temperature. However, despite experimenting with voltage values ranging from 0 to 10 V, we have been unable to achieve desirable results. Instead, we observed the formation of H.

In a subsequent experiment, we modified the electrolyte solution by using 70% phosphoric acid, 15% acetic acid, and 5% nitric acid at room temperature. We increased the voltage to 20 V, resulting in a current density of 30. The electropolishing process was carried out for durations ranging from 30 seconds to 1 minute. Unfortunately, we encountered the same issue of excessive H production, leading to a completely white surface on our samples. We were unable to progress to the final stage of the process.

Additionally, we attempted to use the same electrolyte solution at 30 V for 10 seconds, but satisfactory outcomes were not achieved.

Given the aforementioned circumstances, I kindly request your professional advice regarding the appropriate electrolyte solution and voltage parameters for my future experiments.

Thank you in advance for your prompt response.

Yours sincerely,

Alireza Saravani

If I have an excess of sodium carbonate and add sulfuric acid to it, which of the following reaction takes place having in count that there is an excess of sodium carbonate?:

1. 2Na2CO3 + H2SO4 --> 2NaHCO3- + Na2SO4 (before the firts equivalente point)

and 2NaHCO3- + H2SO4 --> 2H2CO3 + Na2SO4 (after the firts equivalente point)

2. Na2CO3 + H2SO4 ---> Na2SO4 + H2CO3

This is without having in count that the final products are Na2SO4 + CO2 + H2O because of the descomposition of the carbonic acid.

Adding lime in the process, apart from the formation of calcium sulfate compound in the neutralization stage with sulfuric acid,if have the negative effect on the precipitation process of metals from the leach solution?

We have an experiment regarding cellulose nanocrystal from sugarcane leaves that undergoes acid hydrolysis with acid concentration 60% sulfuric acid, 30 minutes at 45 degree Celsius. What recommended molarity or concentration of sodium hydroxide should we use to neutralize the suspension before proceeding to the next step?

We have leached ashes of some plant samples to determine the Ni concentration in the leachate using sulfuric acid. In our method, we have used two concentrations of sulfuric acid (1M and 5M) and three pulp densities (10g/L, 100 g/L and 200 g/L). However, I observed a white precipitate in the filtered samples of the with leachate 5M sulfuric acid, after few days. I tried adding few drops of conc. HCl to dissolve it, but it did not disappear.

What could have caused the formation of this precipitate? Is there any method to prevent it?

I really appreciate your valuable suggestions to improve this.

Thank you

Hi,

To be able to Measure the Total Carbohydrate on my sample, I was planning on using the Total Carbohydrate Assay Kit (Sigma Cat#MAK104). The problem is that it includes a step in which I have to incubate the 96 well plate at 90 degree Celsius for 15min, after adding sulfuric acid.

How can I do this? I cannot use a water bath or Incubator.

Thank you for your help

I am carrying out chromatographic profiling to differentiate two plant species by TLC. One of the species presents a characteristic band with Rf at approximately ~0.40, while the other species presents a band around 0.38. One of the bands is yellow using 5% sulfuric acid, and the other is gray, for this reason I believe they are different compounds, but I would like greater separation between the two, using the same chromatographic system. The mobile phase that showed the best results was Chloroform: acetone (90:10) tried a more polar phase such as chloroform: ethanol (70:30) and other more non-polar phases such as Toluene: chloroform: acetone (40:25:35), however Didn't get good results with any of them. The distance of the route I am using is 10cm. Can someone help me? I believe that my compound of interest is from the lignan class, but I need to confirm.

I have carried out an acid persulfate digest (sulfuric acid + potassium persulfate) for total phosphorus extraction on freshwater samples, but can't find a reference for recommended holding time post digestion. Many sources say that the sample can be initially preserved with sulfuric acid and then held for 28 days in the cold before digestion/analysis. Can I assume that the same holding time would be suitable post-digestion? Many thanks.

The old process uses boiling sulfuric acid as a catalyst to dehydrate ethanol to diethyl ether. I want to find a different set of catalysts that accomplish the conversion at high efficiency

Hello, I made passivation on the Cu tape by just waiting in NaOH, it was necessary to coat it with a film of sulfuric acid and pyrrole monomer. But when an acidic polymer entered the solution, the passivation was gone, that is, it dissolved back. How should I passivation on a Cu tape or Al, in short, a metal surface so that I can produce polymers on it? Are there any publications you can recommend? Thank you

Malachite green reagent 1.2% malachite green in 1.5M sulfuric acid : 8% Ammonium molybdate tetrahydrate in ddH₂0:Tween20 (100:25:2)

The Pi standard solution is in 100μL (from 0μM to 100μM ）in every well add 25μL Malachite Green reagent for 5min then add 10μL 5% oxalic acid. Finally measure the optical density of each well at 630nm.

and the standard curve of phosphate not very beautiful?

[The curve in attachments that x axis is Pi concentration(μM) and y axis is measurement OD630nm]

Thank you for your attention！

Dear researchers

I am working on the activated carbon, which synthesized by sulfuric acid impregnation. From EDS , 3% sulfur content attached to the AC. I studied the this material for Pb2+ uptake, and it can remove up to 100 mg/L initial concentration of lead solution. But, when studied, the selectivity by mixing Pb 2+ with Mg2+. Cu2+ and Zn2+ the material was not selective. May I know the reason.

Here is the supporting data related to the coexisting ions :

Ion Ionic radius Type of acid

Cu2+ 73 Borderline

Mg2+ 79 Hard

Pb2+ 119 borderline

Zn2+ 74 borderline

Thank you all. :)

I would like to determine COD value through dichromate method.

But There is so many titrimetric method not colorimetric....

May I ask you how to do the colorimetric dichromate method..?

This is colorimetric method i found but I couldn't find in detail (concentration of solution) anymore...

•Switch on dry-block heater on 150℃

•Preparing Samples

-Deionized water as reference blanks of 2.5mL in digestion vessel

-Blend and mix the water samples before pouring any volume

•2.5mL of water sample into digestion vessel

•1.5mL of digestion solution (K2Cr2O7) to each digestion vessel

•3.5mL of sulfuric acid •Mix and Starting the dry-block heater on 150℃ for 2hr

Thank you for reading

Please explain how to crystallize a cobalt sulfate(CoSO4*7H2O) solution.

The cobalt sulfuric acid solution was concentrated to about 10% at a temperature of 70℃ using a rotary evaporator.

Then, it is put in a refrigerator at 10 degrees to crystallize.

However, crystallization takes too long.

Please let me know where is wrong with the way I'm doing it.

Hello everyone,

We are trying to follow reactions involving PEG (2000 Da) by TLC, but so far we couldn't stain the starting material after running the plate. We tried iodine vapours, ethanolic sulfuric acid, phosphomolibdic acid and potassium permanganate with no success. Can anyone experienced with this task give us a hand?

Thank you in advance!

We are trying to measure cellulose and hemicellulose content in soil by acid hydrolysis using sulfuric acid. But we are not getting significant peaks in HPLC. Another problem we are facing while determining lignin through loss on ignition procedure. Please suggest/refer to a suitable protocol to overcome this problem.

Phenol sulfonation will be carried at around 105 degrees celsius with concentrated sulfuric acid.

Please for preparation of Salkowski reagent to estimate IAA production on liquid medium, is better to prepare it with perchloric acid and iron chloride, or with sulfuric acid and iron chloride?

I am producing a large volume of Ammonium Sulfate (5000L) by adding 2500L of Ammonium hydroxide (25%) to 2500L Sulfuric acid (45%). The sulfuric acid has some iron impurities. During the reaction, what I observe is at the instant the ammonium hydroxide touches the sulfuric acid, white precipitate is formed and causes the reaction volume to become cloudy. The white precipitate does not disappear during the reaction, regardless of temperature (my reaction temperature reached 80 C). After leaving it to agitate for a while, the white precipitate disappears and the solution becomes clear. My guess is the ammonium sulfate precipitated out, but why would it do that? It did not happen when I did it in lab scale.

Reactor for hydrothermal reaction:

Volume = 100 ml

Pmax = 3 MPa

Maximum operating temperature = 200 °C

Solution:

Nitric acid - 15 ml

Sulfuric acid - 5 ml

Distilled water - 100 ml

I am looking for the pressure to be generated inside the reactor (the equation) to know what volume of solution I can introduce at what temperature without generating the allowed pressure limit.

I have tried to find literature on aqueus dissolution of copiapite. This mineral group causes a lot of acidification with resulting pH values between ca. 1-2,5 (3). However, I cannot find reports on exact dissolution reaction. I wonder if it possibly also involves formation og SO2 in addition to sulfuric acid and would be pleased to know.

Per Hagelia

NPRA

Norway

Dear researchers,

We did the Gerber fat test for milk and sausage, after reacting with acid, the material turns brown and dark purple. What is the exact cause of this color change?

90% sulfuric acid is used for milk and Salvin reagent is used for sausage.

Is it because of antioxidants and nitrite or are proteins involved? Or is it a combination of these things?

Dear Concern,

I'm facing a problem in using acid to neutralize the raw wastewater using Sulfuric acid. Here is my question.

In a Industrial Wastewater Treatment Plant, During lab testing, less amount of 18M sulfuric acid is required to get a pH 0f 7 in the raw wastewater, but to achieve the same neutralization, the plant uses more acid, though. Why?

The tip will be used for scalpel AFM technique but its contaminated with Si. I have tried with low conc. of HF and sulfuric acid in ultrasonication, but the cantilever itself blew away. Normal water or acetone with ultrasound also didn't work.

Is there any easy option for the cleaning, either wet or dry?

Describing some easy option rather than sharing some scientific article, will be greatly cheered :)

Thanks

Swarnendu

Electrolytic polishing is being used in many industrial fields, and acidic solutions such as sulfuric acid are used.

However, some of the papers I read that metal materials are more safe than acidic solutions, and when electrolyzed with ionic and alkaline solutions, they produce better results than acidic solutions.

The price of acidic and nonacid solutions was similar.

So why do you use acidic solutions in the industrial field?

I also wonder if the non-acid solution is more effective than acid solution.

Hi everyone, I would like to understand if there is a way to form heptyl acetate and heptyl heptanoate without the use of a reflux system (using only traditional glassware), and using a sulfuric acid catalyst. so far using the volume of 1.54ml heptanol, 7.44ml of heptanoic acid, and 3ml of acetic acid is not working. The heptanol smell is very much present.

I read an article about the optimization of anthocyanin, flavonol and phenolic acid extractions.

I wondered if these extracts would damage the colon when run with LC or not.

Adjé, F., Lozano, Y. F., Lozano, P., Adima, A., Chemat, F., & Gaydou, E. M. (2010). Optimization of anthocyanin, flavonol and phenolic acid extractions from Delonix regia tree flowers using ultrasound-assisted water extraction. Industrial Crops and Products, 32(3), 439-444.

I am working on terpenes and terpenoids

If you have any suggestions for articles explaining and examining the differences of the two acid types, their radii as dope ions, the electrochemical properties they reflect, and what kind of reactions they cause in doping, please share.

I have been doing routine COD measurement for years in my lab using the conventional titrimetry method. Back then, I used spectrophotometer method once, but the results are not compatible with the results of local government lab using the titrimetry method, hence I went back using the conventional one. I was using Spectroquant kit from Merck for COD measurement. Recently, I was forced to using the spectrophotometer method once again because there is some problems with the sulfuric acid stock. And again, I have the same problem as I encountered before. The results of the spectrophotometer is always way higher from the usual results using titrimetry. I use two sets of kit in range of 100-1500 mg/L and 500-10000 mg/L to determine my samples' COD. When the lower range one results >1500, I use the higher range one to determine the same sample. But the results is way too higher than usual (about 5× higher). My questions are:

1. Is there any limitation of using the ready-to-use kit method rather than titrimetry method?

2. In case of the ready-to-use kit, is there any range preferences inside the range that is mentioned in the kit that affects the accuracy of the method?

For quantitative estimation of IAA, need to prepare Salkowski reagent. In some literature perchloric acid was used and in some, sulfuric acid, so please suggest me which one shall I use? And also about the standard curve preparation?

Thank you, Regards

a) What happens when we suppress the dissolution reaction in anodizing process, will the coating thickness will get higher. There are findings claims that film thickness grows simultaneously when we suppress the dissolution reaction.

b) Could anyone explain the dissolution reaction in anodizing process.

Please don't copy paste the article from internet. I would be grateful if you could give a explanation in a short way according to your convenience.

Thank you.

I am researching about turning WCO to biodiesel but the catalysts that are often use are either sulfuric acid, hydrochloric acid, NaOH, KOH in transesterification process. I wonder if I can proceed do the esterification and transesterification using any acid and base as long as it it strong.

I am doing electrochemical cleaning of bare gold electrode with weak sulfuric acid. Unfortunately, I obtained voltammograms which are very different from that found in literatures. Kindly see attached file for the image of the voltammograms.

positions of C1s,N1s,O1s and S1s peaks is important for me...

I have been into the topic of restoring dead old dry batteries with sulfuric acid rather than replacing the battery with a new one to save some money. But I have my doubts to the practicality and the feasibility of this method. So, to the people of specialty and experts, is this method recommended practical wise and financial wise compared to replacing the dead old battery with a new one?

I am doing oxygen measurements using the Winkler method in marine waters under the influence of riverine inputs. Salinity never goes down 30. Recently, I am experiencing some difficulties to dissolve the precipitate. I read that "In running determinations of dissolved oxygen on fresh or slightly brackish waters, considerable difficulty may be experienced in obtaining complete solution of precipitate" (Codispoti 1988). Why it that so? Organic matter in suspension (I prefiltered under 200 um)? Salinity?

I tried adding some more drops of sulfuric acid (R3), but it doesn't change. I tried to change R3 with HCl 37 %, but it doesn't work either. I found some ref about using AIK(SO4)2.12H2O and NH3) to separate material in suspension, is this working?

Thanks in advance for your help!

I want to modify surface roughness in Polydimethylsiloxane without changing its surface chemistry too much ? I have tried to treat PDMS substrates with sulfuric acid/hydrogen peroxide and then with potassium hydroxide but the roughness has not changed much. I have seen some papers that use plasma treatments, but I only have plasma oxygen in my lab. Could someone recommend any other treatment?

I need step by step on how cellulose Nanocrystal can be prepared from the brewery spent grains via sulfuric acid hydrolysis?

I'm doing extraction of saponin from banana peels. i use vanillin-sulfuric acid assay to but got some error. all my samples become black after incubation and give 3.00 absorbance. may i know what colour i should observe after adding sulfuric acid? 

the procedure  of the assay that i follow from literature review:

-1 ml of sample extract + 0.25 ml 8% (v/v) vanillin + 2.5 ml 72% H₂SO₄

-incubate mixture in 60^oC water bath for 10 minutes, then in ice for 15 minutes

-record A₅₄₄

*when i add acid, the mixture become yellow and darker over time, totally black after incubation

does anyone know any journals that i can refer to regarding this assay? i need to find out the function of vanillin, reaction of acid with my sample/saponin. 

Thanks a lot!

I recently successfully managed to make concentrated sulfuric acid by electrolysis of copper sulfate. I start from a 0.3 M solution of copper sulfate, and turn it into dilute sulfuric acid (0.3 M) with electrolysis. The resulting product is very clean, as all the copper sulfate is consumed, and I use electrodes that are inert with respect to sulfuric acid (copper for the cathode, and lead-dioxide for the anode). Then I boil the water off in order to concentrate the acid. All the steps are shown in my video:

In the video, I achieve a concentration of 83%, but I successfully achieved a concentration of 92% with another batch which I didn't catch on video. In principle, I could boil the acid longer in order to reach the azeotropic concentration of 98.5%. But the problem I am having is that, as I approach a temperature 310 Celcius, some white fumes appear, and I am not sure whether they are due to some impurities that I couldn't get rid of, or if it is the sulfuric acid which starts to decompose.

Any idea on what's going on?

In the following tutorial, I show how to make sulfuric acid from household product, and how to concentrate it:

I initially obtain a relatively clean dilute acid, but when I concentrate it by boiling of the water, I also concentrate the amount of impurities. These impurities don't seem to dissolve, and I can remove part of them by decanting the product. I would like to completely filter them out. However, I cannot use a coffee filter because the concentrated acid instantly reacts with it, adding more pollution.

Are there other way of filtering sulfuric acid?

Hello, everyone !

I am looking for information on the operation of a catalyst in complex form based on stannic oxide / catalysis composite

sulfuric acid allowing the condentation reaction to form allantoin.

I put so attached the original patent and translated into English.

Thanks for your help

best regards,

Thomas

I used 7 g MCC in 100 ml of 65% sulfuric acid. Temperature and hydrolysis time were 40 C and 2 h respectively. After 10 min it's became yellow and at the end it was dark brown.

Want to introduce sulfonic acid group in the seven hydroxyl group of diosmetin, use sulfur trioxide complex, concentrated sulfuric acid does not react

Does anyone know the cause or the mechanism of this reaction

Hi everyone.

I hope you could help me solve this proble:

I am trying to obtain dibenzyl fumarate from fumaric acid and BnOH through Fischer esterification reaction. The problem comes by the use of sulfuric acid as catalyst, that polimerizes and oxidizes BnOH. Although the product is generated, the purification is quite complicated because of sideproducts. I've tried using DCC as acylating agent (with DMAP as catalyst) but same thing happens with sideproducts. The best synthesis i have done till now is acid transesterification of dimethyl fumarate with BnOH in presence of p-toluensulfonic acid. The latter works much better but i can't find a suitable purification method.

Thank you!

Hello, I am working on AAO fabrication on 1050 Aluminum sheet(thickness= 100 um)right now.

I had tried several sets of method through paper research including:

10°C, 40V, 0.3M oxalic acid,

10°C, 25V, 0.3M sulfuric acid,

25°C, 75V, 0.3M oxalic acid,

but all of the above methods only could last up to 30 min then the current dropped to zero, not reported 24 hours.

All samples were cleaned by base and acid bath, then electropolished.

I am wondering about anything could go wrong through the process that made the current fall to zero so rapidly ?

Due to the high melting point of PEEK particles, this polymer is insoluble in many solvents except sulfuric acid. I just wants to know that which solvent can dissolve this polymer. Also, I am so interested to know that does anyone know that haw this polymer can dissolve in the suspension of sodium borohydride?

Thanks

Air Humidity is absorbed by Sulfuric acid 98% that leads to dilution of the acid. the concentrated acid will keep absorbing moisture until it reaches an equilibrium with the ambient humidity. the produced diluted acid has a lower density and accumulates at top of the liquid.

I need to know the depth of the top diluted acid layer.

I'd like to prepare a solution of MoCl₃. According to the supplier, MoCl₃ is soluble in nitric acid and sulfuric acid, and insoluble in water and dilute hydrochloric acid.

Does anyone work with MoCl₃? I'd like to prepare a solution of MoCl₃ with a concentration between 0.1 and 1 M but not using nitric acid as it will give (MoO₄)^2- species. I need to obtain the Mo³⁺ species.

A potassium cyanide solution is required to calibrate absorbance curves in a cassava cyanide quantification protocol.

Therefore, to obtain a stock KCN solution (5mM) for calibration of absorbance values:

1. Dry KCN over concentrated sulfuric acid (H2SO4) in a desiccator for at least 12h

2. Dissolve 125 mg in 500 mL of 0.2M NaOH b

3. Dilute the above 100 times in 0.1 M pH 6 phosphate buffer in a volumetric flask to give a 2.5 μg / mL solution.

Thank you very much in advance

Hi all, can anyone please suggest how to "subtract" the double-layer charge from the total charge in the hydrogen absorption/desorption region of CV (using origin or excel)? Please see the attached image. To get this CV, 0.5 M sulfuric acid was used as an electrolyte, catalyst ink coated glassy carbon was used as working electrode, Pt was used as a counter and SHE was used as a reference electrode. The potential was set between 50 mV to 1200 mV and the scan rate was 20 mV/sec. Please let me know if you need additional details. The purpose is to find the electrochemically active surface area.

I would be happy to connect with anyone working on topics related to fuel cells and electrocatalysts. Thanks

Hi everyone, I have been performing an indirect ELISA to determine antibody titers of mice immunized with three-finger toxins. Up until now, I have given 6 booster injections. I normally coat the plate with 1µg/mL of the toxin and incubate overnight at 4 degrees. Blocking is done with Block ACE for 1 hour at RT. The serum samples are prepared in a 1:1000 dilution in PBS and incubated at 37 degrees for 1 hour. The HRP-Conjugated antibody is prepared in a 1:1000 dilution in PBS. 200 µL of OPD substrate is added and incubated for 1 hour at 37 degrees and subsequently stopped using 3M Sulfuric acid. Plate is finally read at 492 nm. The ODs have not been consistent across several experiment for a single sample. In some cases, the ODs for the negative control (PBS-only mice) is even higher than that of the samples and this is visually observed in the plates. Also, for instance ODs for post 3 samples tend to be higher than those of post 4 and post 5 samples (as can be seen in the attached plate) I am wondering what could be accounting for this lack of reproducibility in the ODs and how that can be fixed. I am also exploring other methods for quantifying antibody titers including the use of UV spec and the measurement of total IgGs using protein A system. Can you share with me your thoughts on these approaches and their suitability for my intended use

In the table attached, I have summarized 4 experiments and the variable ODs across a particular sample. The plate also shows (from left to right) post 3, 4 & 5 samples run in duplicates. The last 2 rows of each pair represent negative control

In the determination of ammonia concentration in a sample gas, trapping NH4+ ions using a sulfuric acid trap is popular. However, I was not certain if there is a method to measure the concentration of NH3 or NH4+ through titration? I am trying a way around using an ion chromatography system.

We have coated certain ceramic thin films on stainless steel as potential corrosion-resistant coatings. The corrosion test will be performed in 98% sulfuric acid at elevated temperatures. But I have coated my substrate on one side. However opposite side is uncoated. As the whole sample will be dipped inside the sulfuric acid solution, the backside (stainless steel) will be also exposed to Sulfuric acid. So, what type of material I should use to protect the backside of my sample from the harsh acid environment which will not compromise the validity of the corrosion rate. Will epoxy or magic work?

Hi everyone,

In my project, i have to prepare CNC by acid hydrolysis (sulfuric acid). To isolate them i used the classical method of centrifugation/redispersion and dialysis until neutral pH. My question is, how i can determine the concentration of CNC after dialyis without using freeze-drying? I saw it was possible to use titration with NaOH to determine the amount of sulfur groups, but not all the hydroxyl groups of CNCs are substituted so i cannot determine exactly my concentration. Does someone know a quick method without using additional equipment?

Thx in advance.

Jérémy

I am doing research on the synthesis of paracetamol. I am preparing acetic anhydride solution with a few drops a sulfuric acid and wish to measure the pH of this solution. However my pH meter keeps giving unstable and unreliable readings. It is to be noted that my pH is very low and i am using the millivolt raw data readings to measure the pH. The mV readings tend to drop to 750mV range if i add too many drops of acid or leave the prepared solution to stir after a long time. The pH probe im using is inLab Routine Pro-Ism.

I have produced oleum by adding sulfur trioxide, SO3, to sulfuric acid. It mostly contains disulfuric acid (also called pyrosulfuric acid) but i think this method is not suitable for laboratory purpose so is there any feasible procedure for the synthesis of oleum for laboratory purpose?

Suggestions will be highly appreciable.

I have four HPLC graphs (for methyl ethyl ketone (MEK) and sulfuric acid and little organic monomers) and I want to analyze them. Is there anyone who can help me with this?

Is there an empirical or theoretical standard value for this (at room temperature) and for different electrolyte concentrations? Is there a resource available that provides a chart of values for common electrode materials in common electrolytes?

What is the purpose of adding MnSO4, Alkali-iodide-azide reagent and Sulfuric acid in winklers method?

1- Absorption of 1 cc of a nm solution of 20 gold particles at 530 nm equals one. Calculate the extinction coefficient of these nanoparticles (consider the light path length of 1 cm).

If we were to put 10 DNA molecules on each of these gold nanoparticles, what would be the required concentration of DNA molecules?

If the reaction volume is 1 mL, how many gold nanoparticles and how many nucleic acid particles will enter the reaction and finally how many “gold nanoparticles associated with DNA”?

2- Dissolve 20 mg of 40 kDa protein in a 100 mm cc phosphate solution. Calculate the concentration of the resulting solution based on molarity and parts per million.

If this protein becomes dimeric, does its concentration change based on molarity?

3-How to prepare a liter of solution containing 0.2 sulfuric acid nitrogen, 0.01 mmol of substance A, 5% v / v of substance B and 20% f / h of substance C?

MW A = 50

MW b = 712

MW C = 240

The molarity of concentrated sulfuric acid is 18.4.

4- There is a substance (4 g / liter) in the solution. The cuvette is 2 cm long and only 50% of the given beam of light transmits. What is the extinction coefficient? What is the molar absorption coefficient if the molecular weight is 100?

5- The absorption coefficient of glycogen and iodine is 0.20 at 450nm light. What is the focus when the transmission is 40% in a 2 cm cuvette?

"Synthetic resins of low molecular weight produced by polymerization of mixtures of unsaturated compounds (primarily indene and coumarone), which have been extracted from the by-products of coal coking (crude benzene) and from the aromatic high-boiling products of petroleum pyrolysis. Fractions containing about 30 percent indene, 15 percent coumarone, and 5 percent styrene are used in the manufacture of coumarone-indene resins. The monomer mixture is polymerized in the presence of boron fluoride, aluminum chloride, or sulfuric acid. Various types of coumaroneindene resins are produced, ranging in color from bright yellow to dark brown and with a melting point between 60° and 140°C.

š Most coumarone–indene, petroleum, and polyterpene resins are produced by carbocationic polymerization using Lewis acid catalysis."

I need the reaction steps of indene and coumarone through cationic polymerization but I can not find it.

Hi Good afternoon everyone Can someone help me please? We are trying to correct the pH of a landfill leachate treatment plant. The pH of the effluent is 9 and we are trying to make the correction to 7. However, this is not possible because tons of sulfuric acid are used up and the pH returns to 9 quickly. The project: Initially we have an anaerobic lagoon and then an aerobic tank followed by membrane treatment.

Thanks

Commercial sulfuric acid contains iron impurity of about 150-175 ppm, I want to remove it to the level below 2 ppm. Work has been done with cation exchange resin to solve the problem but at the cost of deterioration of resin and loss of sulfuric acid concentration. Moreover, it was found that CNTs/GNFs work well as far as decolourization of the commercial sulfuric acid is concerned but not found effective for iron removal from it.

Researchers are requested to suggest the ways and means for improving the CNTs/GNFs adsorption towards iron removal from sulfuric acid.

Thanks in advance.

I'm doing a bioassay with sulfuric acid to be read in a spectrophotometer. Other than glass, are there less expensive options for 96 well plates that can handle sulfuric acid?

Hello,

I am looking for an industrial process that would remove iron ions (20ppm -> 2ppm) from a concentrated sulfuric acid (78% by weight).

I have already explored some solutions:

- Electrodialysis: This process seems to work for high iron concentrations but is not suitable for such low concentrations.

- Ion exchange resin: A resin could be a good solution but I can't find a resin that effectively captures iron ions in a very acidic environment.

Nanofiltration: This technique effectively removes iron ions from sulfuric acid but the filter does not support pH values below 0, so the acid should be diluted and then concentrated.

Are there any other solutions where the ones listed above are the only ones available?

Thank you in advance for your answers

I am using a Bio-Rad column for sugar detection with an RI detector. My mobile phase is 5mM sulfuric acid. When I ran my blank (DI water) I got a negative peak. The baseline was steady before and after the negative peak. If I have a sample peak far away from the negative peak, will it affect to get the actual concentration of the sample?

Generally water alkalinity to clot the dripper nozzle due to salt formation. So bring down the irrigation water pH to 5.5 to 6.5 may useful for prevent for salt formation as well as crop improvement. Please suggest

We need to determine the best type of rubber suitable for the manufacture of rubber compounds used for lining tanks of concentrated sulfuric acid with a concentration of (w/w) 100%

I work in the WWTP of a tannery down in Brazil and lately there's been this one thing that's really bugging me.

I have learned from experience in the plant that when the pH of the aeration tank is around 7.0-7.6, we usually run the plant without any issues, everything works fine. If the pH of the aeration tank gets slightly higher, say about 7.7 higher, the water turns blackish, we start to notice bad odor coming from the tank, and unfortunately the entire neighborhood around us does too.

When the effluent into the WWTP comes with a high pH, we usually give it a small dosage of sulfuric acid before it gets to the aeration tank and we're able to keep the increase in pH to a minimum, still under control.

However, I have noticed lately that for some unknown reason the pH of the aeration tank has been stuck at 7.9 plus/minus 0.2 for a whole 14 days. The inlet to the tank has been receiving small dosages of sulfuric acid to keep its pH at around 7.2, which is good. But still, the tank remains stuck at 7.9!

Yesterday we dumped 350 kg of 98% sulfuric acid into the aeration tank to curb the pH, it went down to about 7.5, but to our dismay after a couple hours it went back up to, guess what? Yes, 7.9!

I believe the blackish water at pH above 7.7 may be caused by ferric chloride we use to precipitate sulfide in the industry effluent.

The DO has been around 4.0. I know a good rule of thumb is to keep it at 1.5 - 2.0 mg/L, but we are running the current blowers at the slowest pace we can, and we use a variable-frequency drive kept at a minimum. I know how excess aeration can strip out CO2 from the tank, thus increasing the pH, but is this the main reason why it is stuck at 7.9?

I believe there must be some buffering happening inside the tank that I am not familiar with. This is the first time it happens. Is the sulfate from sulfuric acid a possible reason for this? Should I change it to hydrochloric acid instead?

I am using chlorosulfonic acid in chloroform (inert, 2 hr, RT) to para-sulfonate benzyl groups on a dibenzyl ether. The work up is extraction with water. The reaction, however, does not seem to work. Are there other reaction conditions and/or work up to try for aromatic sulfonation reaction?

I have tried an alternative, stirring with sulfuric acid for a few days, however, I cannot obtain pure product without large amounts of inorganic salts.

Attached pictures are impeller of CW pump using in a cooling tower (5000 cubic meter pond capacity, 160-190 cubic meter/ hr evaporation rate). Sulfuric acid 400Kg Phosphoric acid 150Kg & Sodium Hypochloride 250Kg chemicals are dosed at 30 ft distance from pump in weekly basis. PH maintained in 8-9.5. Water source : River conductivity 1000-2000 microS/cm.

My Question is : Are these chemicals responsible for corrosion?