Nitric Acid - Science topic

Would someone please help? I have carried out Fenton pretreatment and that has left out a lot of ferric precipitates on my filter paper. So, i have added 50 to 60 % of sulphuric acid onto my GF filters to dissolve the ferric precipitates. Then, I could see that the precipitates were dissolved immediately and then I have washed the filter paper with plenty of millipore water. But, I would like to know whether this process (less than one min of contact between filter paper and 55 % sulphuric acid solution) would affect the chemical nature of my microplastics? Observation in microscope suggests that discolouration has occurred. But I would like to know does any of you has encountered similar situation? What is your recommendation? Thank you so much.

I agree with Enrique Arpa!

Hello

For any molecule you can find the sdf or mol format in pubchem or other chemical databases. You need to convert that file in your required format using some tools. You can use Open Babel tool.

About silver nitrate aq. sol. acidified with nitric acid ― at this forum: https://www.researchgate.net/post/Why_does_silver_nitrate_look_turbid_after_adding_nitric_acid

To make a 1000 mg/L magnesium (Mg) standard solution in 100 mL of 5% nitric acid, you can use magnesium nitrate (Mg(NO3)2). The formula weight of magnesium nitrate is 148.31 g/mol.

Here's the calculation for making 1000 mg/L Mg standard solution:

1000 mg/L = 1000 mg / 100 mL = 10 mg/mL

To make 10 mg/mL solution, you need 10 mg / 148.31 g/mol = 0.06767 g of Mg(NO3)2.

So, you can weigh 0.06767 g of magnesium nitrate and dissolve it in 100 mL of 5% nitric acid. This will give you a 1000 mg/L Mg standard solution that is suitable for use in ICP-OES. It's important to thoroughly mix the solution and make sure it is homogeneous before use.

Any traces of magnesium or calcium at the surface of the steel would very likely leach quickly. You might be able to pre-treat it to leach them away beforehand but I'm not an expert in this area.

No, citric acid trihydrate crystals will not dissolve in room-temperature concentrated (65%) nitric acid.

For concentrated H₂SO₄―HNO₃ mixed aq. solutions, nitronium ion generation reaction is expected to occur between both acids: (i) H₂SO₄ + HNO₃ ⇌ HSO₄⁻ + NO₂⁺ + H₂O. The nitronium cation can combine with the bisulfate anion to to yield nitrosulfuric acid (nitronium hydrogen sulfate); a strong oxidizing agent: (ii) NO₂⁺ + HSO₄^- ⇌ NO₂HSO₄. The nitronium ion can also combine with the nitrate anion, while dinitrogen pentoxide gas can evolve from the solution ― more intensely if hot: (iii) NO₂⁺ + NO₃^- ⇌ N₂O₅(aq) ⇌ N₂O₅(g)↑. This gas can possibly react in gas phase with water vapour: (iv) N₂O₅(g) + H₂O(g) ⇌ 2HNO₃(g). Nitronium hydrolysis, and that of N₂O₅(aq), also occurs: (v) NO₂⁺+ 3H₂O ⇌ NO₃^- + 2H₃O⁺; (vi) N₂O⁵(aq) + H₂O ⇌ 2HNO₃. Sulfur trioxide (SO₃) evaporates along with H₂SO₄ from concentrated H₂SO₄ sol.

Alternatively, but in principle less conveniently, the dilute solution could be prepared gravimetrically as follows.

From mass balance for the solute (HNO₃) on the dilution operation:

{65.0 wt% (solute:solution)}·m_{initial solution} =

{2.00 wt% (solute:solution)}·m_{final solution}

Mass balance for the solution on the dilution operation:

m_{initial solution} + m_{added Water} = m_{final solution}

Common laboratory borosilicate glassware  ̶  often either called 'borosilicate 3.3' or Pyrex® glass ─ is expected to be seriously corroded by concentrated (conc.) aqueous solutions of phosphoric acid above ~120 °C. Use of conc. H₃PO₄ (> 30 wt%) from ~40 ºC to ~120 ºC is also not recommended, in general, but can be found acceptable after carefully consideration of the particular experimental circumstances involved by experienced users. Below ~40 ºC, corrosion is expected to be small, but prolonged contact of the glassware with conc. H3PO4 should be also avoided, particularly when volumetric glassware is used or when contamination of the contained liquid with ions contributed by glass corrosion must be avoided to any appreciable extent. Besides these generic guidelines, it would be also advisable to refer to the technical literature that may be found issued by the glassware supplier.

From steam tables, water alone will have a pressure of 1.553 MPa at 200C. According to Aspen Plus simulator, including the acid will decrease the pressure to 1.388 MPa. However, at 200C, the HNO3 will slowly decompose to NO2 and O2 even after the final temperature is reached. The non-condensable gases from HNO3 decomposition will increase the pressure beyond 1.388 MPa. The pressure increase will depend on the mount of vapour space and the extent of HNO3 decomposition.

Good day, Francis Rey U. Cortes!

Here I have found another SOP: "After 12 h of treatment, the dispersion was placed into an ice bath in order to cool down it to room temperature. The dispersion was centrifuged for 10 min at 3,500 rpm for sedimenting solid residues and separating the supernatant from the mixture. The supernatant was filtered in a Millipore system under vacuum by using a polytetrafluoroethylene (PTFE) membrane of 0.22 lm and they were analyzed through UV–Vis light absorption spectroscopy. The solid residue was washed with deionized water so that the excess of nitric acid was removed from the sample. The washing process of the solid residue was repeated until the filtrate reached the pH of the deionized water. Finally, MWCNTs were neutralized and dried on a polyvinylidene fluoride (PVDF) membrane. The solid residue was dried under vacuum for subsequent analysis."

Here is a link:

Best of luck in your research!

Yours sincerely,

M. Sc. Vadym Chibrikov

Department of Microstructure and Mechanics of Biomaterials

Institute of Agrophysics, Polish Academy of Sciences

Dear Raneesha Navaretam, please have a look at the following similar RG thread. My Regards

I think you may find the response to your inquiry in the following papers:

The mixture of HNO3 and H2O2 looks the preferable for complete plants decomposition.

Dear Asrar Islam

The chemical treatment of activated carbon with nitric acid could add an oxygen functional group. Should your targeted pollutants have an affinity toward oxygen, that should improve its uptake. At the same time depending on the type of activated carbon, the nitric acid could dissolve acid-soluble organic matter from your activated carbon. That may result in a loss of active sites which may result in low uptake.

Please study HSAB principle i.e. Hard soft acid base principle.Strength of the acid can also be estimated by the Hendersion equation Pka and PH value

Dear Julian Torres Julian, you can try to precipitate the treated CDs by centrifugation, remove supernatant, then add a portion of water, do mixing, then again centrifugation, washing of the precipitate and so on up to neutral pH of supernatant.

Dear Shoaib Ajmal . See the following useful RG links:

This is another interesting paper.

10.1039/C5SC03828F

No, dilute nitric acid cannot be concentrated beyond 68% by boiling. It can be concnetrated b y distilling it with concentrated sulphuric acid under reduced pressure . Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% HNO 3, it is referred to as fuming nitric acid. This mixture boils constantly at constant boiling point without any change in its composition. At this temperature, the gas and the water vapour escape together. Hence the composition of the solution remains unchanged. So nitric acid cannot be concentrated beyond 68% by distillation of dilute solution of HNO3.Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%.Fuming nitric acid is a commercial grade of nitric acid that has a very high concentration and a high density. Moreover, it forms a colorless, yellowish or brownish fume. The lowest concentration of this acid is 90%. Concentrated nitric acid is simply a solution containing more nitric acid in less water.

thank you

Naim Aslan and Mohd Faheem Khan

Without the exact composition of the slurry, the carrier used and the treatment conditions nobody can give You the information You are asking for.

Dear Andrea Pasquale many thanks for sharing this very interesting technical question with the RG community. As already mentioned by Paul Körner, a common method for oxidation of galactose to mucic acid (also known as glactaric acid) is the reaction with concentrated nitric acid (68% HNO₃). For a typical procedure, please have a look at the following useful literature reference:

I hope you can access this article through your institution, as it is not available as public full text on RG. In this procedure, galactose (10 gram) is treated with 70% nitric acid (30 mL) containing a small amount of sodium nitrite (1 gram). The reaction occurs between 0 °C (4 hours) and room temperature (no heating required), and under these conditions the resulting mucic acid crystallizes directly from the reaction mixture in 88-90% isolated yield.

The reaction condition which you mentioned in your original question (dilute nitric acid) is also possible, but in this case the reaction does not occur at low temperature. According to an older German textbook (Gattermann, Wieland) 25 gram of galactose are dissolved in 300 mL 25% nitric acid and heated on a boiling water bath until the total volume of the solution is reduced to ca. 50 mL. After cooling to room temperature, the resulting semi-solid mass is stirred with 50 mL of water. After 1 hour the crystals can be isolated by filtration and dried in air to give ca. 15 gram of mucis acid.

I hope this helps. Good luck with your work and best wishes, Frank Edelmann

Agreed with Muhammed Amjad

I have done ECCI on 316L (attached is an image obtain of 3D-printed 316L). for ECCI observation, you do not need to electropolish your samples. In fact from my experience, electropolishing makes it harder to perform ECCI as it tends to reveal too much details about the microstructure under the BSE that it would be difficuly to discern whether the ECCI was performed successfully or not. Here is the procedure I recommend:

1- Prepare the sample as you would for EBSD analysis (moving all the way down to 0.05um with OPS colloidal silica)

2- Make sure you have the proper Field Emission SEM (FE-SEM) as a Thermoionic SEM with Tungsten filament won't work

3- Bring your sample VERY close to the BSE detector, as close as possible while carefully not hitting the detector! You will not need to tilt your sample if you are using a low magnification

4- Turn the brightness to 0% and use only contrast

5- Use an accelerating voltage of 10-15kV and a beam current of 1nA

6- Start with a fast scanning speed in order to locate areas of interest. The area of interest where you want to see the dislocations will typically be brighter than the rest.

7- Adjust your focus/stigma as you zoom in (on our TESCAN MIRA4 this is around 80kx zoom). Note: your focus/stigma must be near perfect.

8- finally, adjust your scanning speed to a very low scanning speed and now you can finally see the dislocation.

good luck!

The best method for extraction of heavy metals namely Zn, Cu, Fe, Mn, Ni, Cd, Pb etc from plant sample is wet digestion with di acid mixture (HNO3: HClO4 ::3:1).

Dear Gideon Sunday many thanks for sharing this very interesting technical question with the RG community. As already indicated by Sengottuvelan Balasubramanian it would be helpful if you would specify which kind of inhibition you are interested in. I assume that it's corrosion inhibition of the copper surface. In this context, please have a look at the following potentially useful article which might help you in your analysis:

This paper has been published Open Access so that it is freely accessible as full text on the internet (please see the attached pdf file).

Good luck with your work and please stay safe and healthy!

Dear Leonardo, sorry to see that your very interesting technical question has not yet received any expert answers. To the best of my knowledge, the classical synthetic protocols for preparing rhodizonic acid from inositol always use nitric acid. For example, please have a look at the following detailed procedure:

Even a tutorial video has been published in which this synthesis is illustrated:

If you run this preparation in a well-ventilated fume hood on a relatively small scale (e.g. 10 grams) this should present no real danger. As chemists we should know how to safely handle toxic and potentially dangerous materials. By the way, rhodizonic acid is also available from commercial sources (just in case that you need only a small amount).

Good luck with your work and best wishes, Frank Edelmann

Dear Wayne Edgar Alphonso sorry to see that your interesting technical question has not yet received any expert answers. Unfortunately I'm absolutely not an expert in this field of research. However, I made the experience that a lot of useful information is available right here on RG. It often pays off when you search the "Publications" or "Questions" sections of RG for certain research topics. In this case, please have e.g. a look at the following potentially useful article which has been posted as public full text on RG:

The following literature reference is a review article which should provide you with a good overview:

The paper has also been posted as public full text on RG and can be freely downloaded as pdf file.

Good luck with your work and please stay safe and healthy! With best wishes, Frank Edelmann

Dear Muhammad Awais Akhtar thank you for posting this interesting technical question on RG. To the best of my knowledge one of the most effective ways of purifying MWNTs is heating with nitric acid in a closed vessel under microwave irradiation. For this you just need a thick-walled glass tube with a screw cap. The procedure is described in the Abstract of the following article:

Unfortunately this paper is not freely available as public full text on RG. However, a very similar procedure is described in detail in the following interesting paper:

(please see attached pdf file)

I hope this helps. Good luck with your work and best wishes, Frank Edelmann

Dear Prince Hotor sorry to see that your interesting technical question has not yet received any expert answers. Although we published two lignin-related papers n the past, we never investgated lignin nitration. Thus I'm not really a specialist in this field. However, I can suggest to you the following potentially useful review article:

This article is freely available as public full text on the internet (please see attached pdf file). On page 6497 is has a section on nitration of lignin in which a few original research articles are also cited. I hope this helps. Good luck with your research!

To use a condenser.

You will probably want to keep the matrix of your samples and standards as similar as possible. If your samples are in 1% HNO3, try to keep the final concentration of calibrants as close to 1% HNO3 as well.

If you are concerned about it, try a simple experiment where you increase the acid concentration, and see how that affects your results. Also, test out how repeatable your results are by measuring the same samples over several days, that will show how consistent your results are. Errors of 1-5% might be quite normal for your matrix and instrument. Maybe even 10% if you're at the low end of detection.

In principle, the cleaning of this type of device can be found in its instructions.

However, to avoid problems, you can directly contact the manufacturer of ICP (Agilent ICP- MS 7900)

it depends on the decalc. rate for both interior and postiror .. pls see this link

Bruce Landry

I believe you are referring to metallic copper. The atomic mass is

63.546

The molarity should be 2.3451/63.546 per L

= 0.0369 M

use M1V1=M2V2

M1= initial molarity

V1= initial volume

M2=final molarity

V2=final volume

then

0.0369 M x 10 mL=M2x100 mL

M2=0.00369 M

ask other member to double check

As it is probably ; first experience in this issue , kindly read some references :

and about the method , find the attached file, hope it can be useful for you!

Which acid combination is more suitable for soft tissue digestion?

Dear Mohammad Jazirehpour many thanks for posting this interesting technical question. The preparation of Y(NO₃)₃􏰀x6H₂O powder has been reported in the article cited below. It was obtained by dissolving yttrium oxide in 6 M nitric acid:

From our own experinence I would suggest the following procedure: Place the nitric acid in a beaker and heat it to ca. 50-80 °C. With stirring, add a little more than the calculated amount of Y₂O₃ and let the mixture stir until most of the oxide has dissolved. A small excess of oxide is useful to completely consume the acid. Then filter the mixture and evaporate the clear filtrate until crystals begin to form. Pour the hot solution into a crystallization dish and let it stand at room temperature over night so that the remaining water evaporates. Then collect the product.

Good luck and best wishes, Frank Edelmann

About predicting the pH of citric acid ― sodium citrate solutions and buffers for approx. pH < 4.0 ― cf. my post at:

About predicting the pH of citric acid ― sodium citrate solutions and buffers for approx. 4.0 < pH < 5.5 ― cf. my posts at:

About predicting the pH of citric acid ― sodium citrate solutions and buffers for approx. 5.5 < pH < 8.0 ― cf. my posts at: https://www.researchgate.net/post/Why-the-pH-of-Citrate-buffer-increases-when-diluted-with-water

About predicting the pH of citric acid ― sodium citrate solutions and buffers for approx. pH > 8.0 ― and for approx. pH > 9.0 ― cf. my posts at:

Dear Leah Dillon, please check the attached files. My Regards

You may prepare solution of MoCl3 in 5-6 M HCl but the work is to be done in a Ar or N2 - filled box or in isolated vessel filled with N2.

Dear Abed Lina

I agree with Carlos Araújo Queiroz . He is right this ratio is the volume dilution ratio in water. You have to use pure water. Then if prepare 120 ml of diluted acid

you 120/6=20 ml of concentrated nitric acid to 100 ml of pure water.

In the mixing process you have to add the acid slowly to the water and not the reverse.

Best wishes

this may be due to interference reaction in the solution

Dear Maria V Mukhina many thanks for your interesting exchnical question. Concentrated nitric acid easily turns yellow or even brown upon storage due to dissolved NO₂. That's why it is advisable to store nitric acid in brown bottles because the decomposition is accelerated under the influence of light. If you don't have access to fresh nitric acid, older samples can be purified by distillation under normal pressure. On the other hand, I wonder if for the etching of glass very pure nitric acid is required? My personal suggestion would be to just go ahead and give it a try using your yellow nitric acid.

Good luck with your research! 👍

Maybe you want to check:

To synthesize 5-nitro-2-hydroxyacetophenone heat 2-hydroxyacetophenon with coc. HNO3 and Conc. H2SO4 in 1:2 proportion for one hr., then pour in ice water mixture. The product will separate out.

Zain Pirzada

You are confusing 2 different things as Gustavo Henrique de Magalhães Gomes states. It's analogous to saying aren't silver and gold the same because they're both elements? Or confusing a tractor with a car when the function of these 2 vehicles is totally different. If one chemical or physical technique solved all our problems why do you think that there'd be literally hundreds of them.

Things to consider - look at the penetration depth of each technique; look at bulk versus surface composition; structural versus chemical composition, and so on.

Now XRD probably needs at least 1% of another phase to be detectable. In the case of wanting elemental analysis you may want to go to XRF (and will you say that they're the same because they both use x-rays?) or ICP.

We don't go to our car with a single tool - we have a suite of tools to fix the car. In the same way, in the laboratory, different techniques provide different information about our sample(s).

Ask your colleagues, professors, and library what text books they used. In my day, now being a curmudgeon, I used Klug and Alexander as my go to XRD book: X-Ray Diffraction Procedures: For Polycrystalline and Amorphous Materials H P Klug, L E Alexander John Wiley & Sons, New York, NY (1954) - you can get a copy on Abebooks for less than $10 including shipping within the US. We only had IR and UV-VIS in my day - computing wasn't at a stage to allow FTIR. So you can see how much has changed in a person's lifetime...

For related RG discussion:

Maybe buy a commercial product ...

Hello if your acid is pure and analytical grade the the molarity or pH influence in results will be negligible. The optimal concentration of acids in injecting solution is bout 2%.

Perhaps of some interest to this query ― About ammonia gas scrubbing with nitric acid at this forum ― addressing heat of dilution and enthalpy balance: https://www.researchgate.net/post/What_is_the_heat_reaction_for_Ammonia_gas_scrubbing_in_60_nitric_acid_solution

At first you need to implement all reactions and interaction parameters relevant for the distribution between solvent and aqueous phase. That will in your case include dissociation of acids etc. You may find the equilibrium constants in literature or have to estimate them from experimental data. When everything is implemented you can check the conformity of the model with experimental data for binary or ternary systems. If the module agrees with the data you can use it in the process simulation.

Also check https://www.mdpi.com/2297-8739/6/1/3/pdf

Very nice question.

Thanks Curtis!

Hello Mr.Grice

Some good leaving groups like tosylate ,tms ,.. are good.(base on reported works)

But halids are relatively inert in some reactions .

Use of I as leaving group in allylic position is a Conventional method but problem is cost.

Nucleophilc replacement of NO3/X since Hughes & Ingold is Well known but other cations participation or catalysis is unkown...

According to your needs, BOC Sciences can provide you with liposome encapsulation efficiency testing services based on high-performance liquid chromatography (HPLC) combined with molecular exclusion chromatography.

Details link: https://liposomes.bocsci.com/solution/liposome-drug-encapsulation-efficiency-measurement.html

no idea.

regards

Hans

Ask any Chem. 101 student.

Dear V. G. Rousseau, information are available via this forum. My Regards

Dear Rajesh Be and Ammar J. Alabdali, as suggested by Carlos Araújo Queiroz use the preparation described in the Brauer Handbook. Ga metal or Ga₂O₃ are dissolved in nitric acid and the resulting solution is repeatedly evaporated to dryness and the residue redissolved in water. The acid-free solution is then diluted with water so that 100 mL contain 26 g of Ga. From this solution, Ga(NO₃)₃ x nH₂O crystallizes upon standing at room temperature for 1-2 days..

I think yes...please do experiment

Dear W. P. R. T. Perera

I fully agree with the opinion of Professor Frank T. Edelmann , Please find the attached paper which may give you further informations

Regards

Please check the following link, I hope this can help:

Dear Agne Šleiniūtė, all polyurethanes are prone to oxidative dégradation under both acid and alkaline conditions. The kinetics of such a process depends on many variables. To quote : the type of polyurethane, linear or crosslinked, hard or soft segments, polyether or polyester PU, foam (or not) with open or closed cells, the hardness of the oxidizing agent, water content is essential for fast degradation, and others.

Acid hydrolysis is one process used in recycling PUs.

The attached file brings further détails. My Regards

Farhan Ali You're welcome. I hope it worked!

Hi Aurélie Zouaoui, in this case the L-ascorbic acid acts as reducing agent. It reduces the Mo(VI) to a somewhat lower oxidation state between +5 and +6 (see Wikipedia article "Molybdänblau"). In both cases the addition of ammonium vanadate is not necessary.

Hi Vidushi Srivastava , concentrated nitric acid alone cannot form crystals. Even pure nitric acid (100%) is a liquid at room temperature. Its melting point is well below ambient temperature (–42 °C). Like my guess is that the crystals consist of some nitrate salt formed e.g. due to the presence of ammonia or an organic amine.

Dear Feras Rabie, formally, zif-8 is the neutral zinc(II) salt of 2-methylimidazole. In the solvothermal method (see attachment) using excess 2-methylimidazole and DMF as solvent the zif-8 products precipitates from the reaction mixture and is purified by washing with DMF and methanol. As you used an excess of 2-methylimidazole (MeIM), the nitrate anion will end up as 2-methylimidazolium nitrate, [MeIMH]⁺[NO₃]^-, which is washed away with DMF and methanol. Thus it will not be paired with the Zn in the product.

Hi Melissa Beltran, as you said, pure bismuth bismuth complexes comprising thiosemicarbazones as ligands are normally yellow, orange, or red in color. As Marcos Cota stated, hydrolysis and formation of Bi₂S₃ might be a possible reason for the observation of a dark precipitate. If that is the case, hydrolysis could be avoided by using dry methanol and anhydrous BiCl₃ as starting material. You might as well consider the fact that some bismuth(III) complexes can be light-sensitive.

Of course concentrated acid as: 0.2g air dried sample + 10 ml H2SO4 (conc.) heating then add carefully about 5 ml H2O2 (one time or two time 2.5 ml per one). and finally you will get stable colorless solution will be diluted to 100 ml in volumetric flask using distilled water and you should make a blank (all previous procedure but without sample). Good luck

Thank you Hurst and Virgilio for your suggestion, i have tried with 5% HCl with 2% Nitric acid now the recoveries consistent withn in limits.

Greetings..

The most suitable dissolving solvent for digestion of plants samples for heavy metals determination is a mixture of (Sulfuric acid + Per chloric acid + Nitric acid) by ratio 1:2:10

Thank you

PbS shows a very low solubility in water, and it is insoluble in organic solvents. Any "dissolution" process in acids (hydrochloric acid, nitric acid, aqua regia) is accompanied with a chemical reaction whereby H2S is liberated and the corresponding soluble Pb2+ salts are formed. In nature (soil, minerals) PbS is most likely formed under hydrothermal conditions.