Search results

  1. duchuy

    Which ether solvant must we ban when making grignard reagents?

    Hi, I'm I supposed to find an ether with acidic hydrogens or a very strong electrophilic centre? I'm trying with acidic H but it doesn't seem to be working... Please help me thank you!
  2. duchuy

    Maximum flame temperature during Combustion of CH4

    Thank you sir! My excuses for my math. They gave the heat capacity of N2 for the following question that asks about the combustion in 20% O2 and 80% N2. This question is for combustion in 100% O2. But again, thank you so much for your help! By the way, I found 2280K for the combustion in 20%...
  3. duchuy

    Maximum flame temperature during Combustion of CH4

    Hi, I have to calculate the maximum flame temperature of the reaction above. The answer is 4805K but I didn't manage to obtain that answer. Please help me find my error, thank you so much! The values of C are below the solution attempt.
  4. duchuy

    Chemistry Methylation of glucose (mechanism)

    Hi, I don't understand why this correction would be a nucleophile substitution? From what understand : The O atoms in the cyclic glucose acts as nucleophiles. ICH3 is also a nucleophile due to the presence of iodine's "non bonding electron pairs" (sorry I don't know the right term for this), and...
  5. duchuy

    Chemistry E1 reaction on levosalbutamol

    Hi, I have to determine the reaction mechanism of this molecule. Can someone please explain to me why the reaction would occur on OH (A)? Is it bc you can't have 2 pi bonds next to each other and OH(A) is the only polarised bond in the molecule where it would easily break off and form a double...
  6. duchuy

    Chemistry Carbocation stability

    Hi, Sorry in advance if the vocab is incorrect, i'm translating this from french. In the correction, it's written that the 4th carbocation is the less stable due to the attracting inductif effect of the carbonyle group. But isn't this carbocation stabilised by the mesomer effect of the C=O bond...
  7. duchuy

    Chemistry Elimination reaction (E2)

    Hey, I have this equation in which I have to determine its reaction mechanism. I managed to determine how we managed to obtain this the molecule in the picture above, but I don't understand the mechanism behind obtaining the second alkene. Thank you so much for your help, and sorry if the...
  8. duchuy

    Chemistry Carbocations stability

    Thank you for your reply sir!
  9. duchuy

    Chemistry Carbocations stability

    Hi, I have to determine which molecule ( 2 and 3) is more stable. I tried to determine the stability using the inductive effect, but when I tried to that, I ended with molecule 2 being more stable than molecule 3 since: x3 ch3 will push electrons towards c+ Whilst in the 2nd molecule the is a H...
  10. duchuy

    Iodine 131 β- disintegration

    Ok I see thank you so much for your help. So in case where I'm using I-131 to detect hyperthyroidism by scintigraphy, the sensors should surround the patient completely because gamma photons are emitted in all directions right? And again, sincerely, thank you sir!
  11. duchuy

    Iodine 131 β- disintegration

    What's happening in the diagram is actually what's troubling me. Iodine's nuclei decays into an excited xenon atom. The excited xenom atom emits gamma photons to attain a lower and stable energy state by emitting gamma photons. Therefore the nuclei that emits gamma photons is the excited...
  12. duchuy

    Iodine 131 β- disintegration

    Yes, sorry, I am talking about I-131. But I don't understand how the gamma photon is produced and I can't seem to find an explanation for the origin of the gamma photon emitted by I-131's nucleus. I see how gamma radiation is produced by the excited Xe nucleus, but not by iodine's.
  13. duchuy

    Biology Iodine 131 for hyperthyroidism (β- disintegration)

    Hi, I'm struggling to understand an answer in my MCQ. It states that a scintigraphy would detect γ photons emitted by the iodine's nucleus, and the answer was correct. But I don't understand how it would detect γ photons from the iodine's nucleus since it disintegrates by forming Xe*, an...
  14. duchuy

    Iodine 131 β- disintegration

    Hi, I'm struggling to understand an answer in my MCQ. It states that a scintigraphy would detect γ photons emitted by the iodine's nucleus, and the answer was correct. But I don't understand how it would detect γ photons from the iodine's nucleus since it disintegrates by forming Xe*, an...
  15. duchuy

    Altitude of Geostationary Orbit

    Probably I have, but I'm not quite sure how I would use those formulas for an object in geostationary orbit... and i'm taking physics as a minor so I don't really remember much
  16. duchuy

    Altitude of Geostationary Orbit

    Hi, They gave me this formula T = 2piR / v, with T the revolution period of the satellite, R the distance between the center of masses and v the velocity. They gave me the value of G and the eath's mass and asked to determine the value of R. I don't even see fromwhere I should start... Thank...
  17. duchuy

    Ballistics -- How deep does the bullet penetrate into the wood?

    oh my god the answer is actually in cm, thank you so much! how'd you figure that out...?
  18. duchuy

    Ballistics -- How deep does the bullet penetrate into the wood?

    Hi, I was given this exercice where I have to calculate the penetration distance, knowing that m = 20g, v = 300km/h and C = 750 N and I have to give the results with two significant numbers. I really thought that all I had to do was replace the values so I did : d = (20.10^-3) x (300/3,6)^2 /...
  19. duchuy

    Available energy in β+ and β- nuclear reaction

    I think that the prof doesn't like negative signs, so instead of using the energy released which is going to have a negative value when we consider the system, he just uses the available energy so the energy would be positive. I didn't get the chance to ask him since all classes are uploaded...
  20. duchuy

    Available energy in β+ and β- nuclear reaction

    I think it's the available energy in an atom with either an excess of neutron or proton depending on the β radioactivity. I'm not quite sure though sorry, it's just what's written in the text that we have to learn...
  21. duchuy

    Available energy in β+ and β- nuclear reaction

    I'm so sorry for that. Ed represents the available energy. The formula Ed = [Mn(X) – (Mn(Y) + m(e))] c2 uses the mass of the entire atom and is used for β+ and - reaction. But when only the mass of the nuclei are given, we end up with two different formulas : Ed = [M(X) – M (Y)] c2 for β- Ed...
  22. duchuy

    Available energy in β+ and β- nuclear reaction

    Hi, I understood that to calculate the available energy in these two reactions could be calculated from Ed = [Mn(X) – (Mn(Y) + m(e))] c^2, but when I have to change use the atoms' mass instead of the nucleons' mass, it gives out two different formulas : Ed = [M(X) – M (Y)] c2 for β- Ed = [M(X)...
  23. duchuy

    Determine initial velocity of a vertical throw

    Oh ok ok I got that thank you two so much! For the displacement after 40swouldn't it be 40m? For the velocity I'm not quite sure.. I really thought that it would be 0 since it's the moment the ball landed..
  24. duchuy

    Determine initial velocity of a vertical throw

    I think the thing that what's stopping me is that I dont know whether the time an object takes to go up is different from the time it takes to go down.. Because Ive been considering that it's different, so i didnt really manage to write the equation.. At 4s, wouldnt the velocity be 0? If I...
  25. duchuy

    Determine initial velocity of a vertical throw

    But in this case wouldnt I have to values of gravitational acceleration? When the object is going up, acceleration is negative and when it goes down, it's positive. Therefore I couldn't use the 4 seconds value because ( i think ), the time the object takes to go up is different from the time it...
  26. duchuy

    Determine initial velocity of a vertical throw

    Well, i'm also trying with v = v0 + at but I didnt really work out.. This is why I chose medecine physics is so so hard..
  27. duchuy

    Determine initial velocity of a vertical throw

    Hi, I was given this problem saying that a ball is thrown vertically up in the air and returns to its initial position after 4 seconds. The acceleration due to gravity is given to be equal to 10m/s^2. I tried to attempt this problem by using the equation : v^2 - v0^2 = 2ah by considering...
  28. duchuy

    Determine the acceleration of a puck on an inclined air hockey table

    No they didn't give out the value of the angle alpha. That is actually the following question where I have to determine its value, but without acceleration, I can't really finish the exercice.
  29. duchuy

    Determine the acceleration of a puck on an inclined air hockey table

    No i do not know the correct answer. This is a picture of the exercice. It's just indicated 1:1 ratio. I have zero idea about what is the equivalence of the distance I measured with a ruler. So I just decided to use the distance I measured with a ruler to put in the excel. And also i'm supposed...
Top