1. D

    Hardest SNAr Regioselectivity Prediction

    During one of my internship in a big pharma in San Francisco, I had to prepare a new core by SNAr on a tetrahalopyrimidine. Link to Reddit post Predicting the regioselectivity of the second SNAr may seem obvious to an experienced eye, but take your time and explain. Will the substitution occur...
  2. N

    How do I calculate the concentration of a stock solution?

    How do I calculate the concentration of a stock solution prepared in a 100cm3 volumetric flask that contains 75mg of Acesulfame K, 50mg of Saccharin and 200mg of Aspartame ?
  3. P

    Need help extracting MnO2 & ZnCl2 from solution!

    Hello everyone. I'm new to the forum (this is actually my first post) and please let me apologize in advance if my question belongs in another part of the forum. I do possess a solid scientific background (well that's relative... I didn't study science in college, but I am far from the average...
  4. T

    Chemicals for Binding of ammonia in Aqueous Solution

    Hi There, I use sodium formaldehyde bisulfite for binding of ammonia in water. I also use it for removal of chlorine. Am wondering if there are any other chemicals that will bind ammonia in an aqueous solution that are not formaldehyde based?
  5. T

    Detection of cations in a solution

    I have a solution that contains Pb, Cu, Fe, Co, Ni, Zn cations which i acquired from brumer. I don't need to separate them but need to detect each of them. It doesn't have to be in the same test tube though. How can i best detect these cations?
  6. T

    Do sulfates in solution disable reduction of compound with SnCl2?

    I use SnCl2 (from brumer) as a reducing agent. However, i'm not sure if sulphates present are a problem and if they disable reduction of the ions that I want to reduce? Do sulphates react to SnCl2?
  7. R

    Material compability with dsinfectant solution

    Hi, I have a question that i need help with please with my study. I am doing some material compatibility work with chlorine solution disinfectant. I have immersed the various materials (polymers, rubbers, metal) test specimens in the chlorine solution for 30 hours. I have weighed the test pieces...
  8. D

    Stock Solution Question

    If I have a a 40% solution and a 95% solution, how much of each do I need to make a 70% solution with a final volume of 375 ml? My 30 credits in chemistry was too many years ago and I'm out of practice (and stuck.). I've been playing around with the stock formula and algebraically rearranging...
  9. M

    Recommended Solvent for removal of Silicone residue from Molded Polyurethane parts.

    I am using a release agent for polyurethane resin moulded parts. The release agent is a solution of silicone (oil?) in Heptane, Petroleum Naptha and an Aliphatic Solvent. Could someone...
  10. E

    Simple solution question

    Hi all, I have a very simple problem but for some reason I am having trouble with it. I need to dope 0.5g of solid powder with element X to a concentration of 500ppm. I have a solution containing 1000ppm element X. How many mL of this solution do I need to add to the 0.5g of powder in order to...
  11. M

    Sodium Hexametaphosphate Solution

    Hello, I'm not a chemistry person but I am looking for some help to ease my curiosity. I need to make a dispersing agent and the only instructions I have are as follows: A solution of sodium hexametaphosphate shall be used in distilled or demineralized water, at the rate of 40 grams of sodium...
  12. D

    Dilution of a solution of phenol with trichloroacetic acid

    Hello, I would like to solve the following problem: I have a vial of trichloroacetic acid (TCA) at 30% (w/w) in aqueous solution. I have a vial of phenol 88% (w/w) in aqueous solution. What volume of phenol and volume of TCA should I mix to obtain 5 mL of solution where the phenol...
  13. P

    Solution Stability

    I am hoping to bring a product to market based on the work of researcher H. Y. Mohan Ram. I am happy to provide a link to Ram’s work if need be. The Formula: Part A: .5 grams silver nitrate is stirred into 500ml. distilled water Part B: 2.5 grams sodium thiosulfate (anhydrous) is stirred into...
  14. S

    Finding pH of solution (KOH, HCl, NaCl)

    Solution made of 230 mg KOH 8.71 ml 0.802 mol/l solution of HCl 3 g m/m% NaOH = 3.97 diluted to 618 ml m/m% is weight percent of substance. What is pH of this solution?
  15. M

    Density of sucrose solution

    How do I calculate the density (g/ml) of a sucrose solution if the concentration of the sucrose (g/L) in the solution is known? I can solve this problem if I know the concentration of sucrose on a wt/wt basis (g/g). For example, if the density of a sucrose solution is 150 g/kg, in 1 kg of this...
  16. E

    Red flame solution

    Hi, Im new to this forum and i will be greatful if someone could help me with my questions. I dont know much about chemistry but my mission is to mix a liquid fuel that burns with a red flame and it cant be too toxic or highly flammable. So i have to mix a fuel that burns with a non yellow...
  17. M

    What remains after water evaporates from sulfuric acid Solution

    Hi, I have a 5 gallon bucket that was 1/2 filled with an H2SO4 solution (15% by volume). The solution also had 6051 aluminum rod that was sitting inside. After sitting for several months, all of the water has evaporated and a portion of the aluminum tubing has corroded away. What is left...
  18. T

    Calculating potential of a solution

    Hi I'm having some trouble with the following problem: Calculate the potential of a solution made by mixing equal volumes of 0.20M thallium(I)nitrate and 0.20M dibromine in 1M HCl. E°'(Tl3+/Tl+) = 0.77V en E°'(Br2(aq)/2Br-) = 1.087V The answer given is 0.934V This is what I have so far...
  19. M

    Solubility of Silicic Acid

    The question I have is what is the difference between these two forms of silicic acid. Looking at the chemical formula, one can see one is in hydrated form and the other one has water, but not explicitly mentioned in the formula, it just says hydrate. But the molecular weight is different, for...
  20. H

    How to neutralise NaOH and Na2SO3 solution

    Hello I need help to find out how to calculate acid volume to neutralise alkaline solution of 0.5mole NaOH and 0.5mole of NaSO3. I am going to use HCl probably about 28%. The solution is used for desalination of metal objects. The capacity is about 250litres. I will be appreciated for help and...