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chenbeier

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Everything posted by chenbeier

  1. 1 ppt = 1 ng/ kg NaCl molar weight is 58,5 g/ mol, Na molar weight 23 g/ mol The ratio is 1 g NaCl is equal to 0,39 g Na So 1 ppt NaCl is 0,39 ppt Na = 0,39 ng/kg Na 100 ppt correspond to 39 ng/kg For the volume you need specific gravity of the solution. Probably with this low concentratian it's 1 g/ml
  2. Microplastic is added in some products, like shampoo, hairdressing agents, washing powder, etc. So it comes automatically in our water by using it. Plastic Material itself has a long shelftime. But by sunlight, biological enzymes it will be destroyed over years down to small particles like microplastic itself.
  3. I think its 1/1.5 * 100% = 66,6%
  4. What does dosing 100mg and Tmax 2-4 h mean. You have a start concentration of 363,3 ng/ml, you have given half life time 11.21 h and a time 5 days Decay rate is 0.5*A(0) = A(0)* e^(-k*11.21 h) -0,693 = - k* 11.21 h => k= 0,06183*h^-1 5 days = 120 h A(5d) = 363,3ng/ml* e^(-0,06183*h^-1*120h) A(5d) = 0,217 ng/ ml is left after 5 days. Where do you put the 100 mg and the Tmax.
  5. I worked also in a metallographic lab. I know this problem, we used the etchchemical in this way that either the whole microsection of the sample was immersed into the etching solution in a small bowl or a Q tip was used and wiped over the sample followed by good rinsing. Changing of the receipe guide to different etching results. Also the etching glue sticks to strong and cannot removed quick enough to avoid over etching.
  6. I am not sure what medical test you talking about, but we dont give suggestion for medical application. So a admin should take Action maybe.
  7. It is like other compounds, it takes time to dissolve. Help will be stirring, shaking, air agitation and/or heat up to warmer temperature.
  8. Are you kidding and not thr same Person. Read here http://www.chemikerboard.de/topic,22708,-wie-stelle-ich-phenibut-aus-gaba-her%3F.html
  9. Oxidation agents like bleach, oxyclean, Peroxide and alkaline solution like caustic soda, should destroy the colour.
  10. I dont see a oxalate here. B2O5 4- is diborate. Boro oxalate are B(C2O4)2^- or BX2C2O4^- https://en.m.wikipedia.org/wiki/Borate_oxalate
  11. There are 2 types of geometric isomers, 'cis' and 'trans'. -cis isomers: when similar groups are present on the same side of the double bonds, then they are termed as cis. - trans isomers: when similar groups are present on the opposite sides of the double bonds then they are called trans isomers. Cis and trans 2- Butene are examples.
  12. Anode is the electrode where oxidation takes place, cathode where reduction takes place. It has nothing to do with positive or negative.
  13. The Anode is made by zinc. It has an electron pressure to get dissolved. Zink eat the OH - and release the electrons into the wire., that the reason more and more OH- will sucked there. The opposit takes place at the cathode.
  14. That is also not right. In the electrolyte the negative charged Hydroxid ions release electrons into that electrode to be prepare to travel throw the outer circuit. So this electrode the Anode get negative charged, Oxidation takes place as described above. Zn + 2(OH)- = ZnO + H2O + 2e- The electrons travel thru the wire and the consumer resistor to the Plus electrode the cathode. Here a Reduction takes place the electrons are used to reduce that material like this equation. 2 MnO2 + H2O + 2e-==> Mn2O3 + 2(OH)- The OH- are like ferries to bring the electrons from the cathode thru the solution to the Anode.
  15. In US Aluminum in Rest of the World Aluminium. Story here https://www.uh.edu/engines/epi1087.htm
  16. Why not? Alkali or earth alkali sulfates can only reduced with aluminium, calcium, sodium and others.
  17. But you have 12% , what you can dilute. Calculation shown above. By the way where do you live?
  18. I think the moderator should close this topic now. Nothing more to say. By the way there are also receipies for elefant toothpaste by using 6% H2O2 in the net. https://www.scholastic.com/parents/kids-activities-and-printables/activities-for-kids/math-and-science-ideas/home-science-experiments-elephants-toothpaste.html
  19. Let it be. Very dangerous, if not right Equipment and stabilizers are used. Increasing of concentration will end up with explosions. Its safer and cheaper to buy 32% H2O2 and dilute down to 24%.
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