Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
We recently did a lab/demo using the NMR to observe Na ions in sodium complexes in our Inorganic Class. I understand most of the post lab questions, but there are a few that still have me stumped. Essentially what we did was create two samples: in one we added NaI to 18-crown-6 ether (with enough deuterated acetone to lock the signal) and in the other we just added NaI to deuterated acetone. 1M NaCl was used as a standard. The resulting peak of the Crown solutiion was shifted downfield approximately -17 ppm from the NaCl standard. The peak from the Na in pure acetone was only about -1.7 ppm down from the standard. My questions are as follows:
1) How would you make the Na-23 NMR peaks "sharper" for NaI/18-crown-6 ether samples?
2) Why did we acquire all spectra without rotationg the sample?
3) Why are Na-23 peaks shifted to lower ppm values when sodium is encapsulated by 18-crown-6 ether
4) How would our results change if a cryptand, such as [2,2,2]crypt was used instead of 18-crown-6 ether.
I was also wondering why sodium present in the glass NMR tube does not show up on the spectre? I realize it is in the solid phase but what effect does that have?
What is the minimum amount of 6.0 M H2SO4 necessary to produce 20.0 g of H2? according to the following reaction. 2Al(s)+3H2SO4(aq)-->Al2(SO4)3(aq)+3H2(g)
Define internal energy and enthalpy. What is the difference between the two? List the following gases in order of increasing root-mean-square speed, all at the same temperature: H2, He, O2, Ne
Reversible adiabatic processes are isentropic. Are isentropic processes necessarily reversible and adiabatic?
Choose only the mixtures that constitute buffer solutions. Can someone how i would determine this as well? 0.30 M HOCN mixed with 0.35 M NaNO3
A sample of an unknown metal has a mass of 35.4 and a volume of 3.11 . Whats the Density?
A sample consisting of various gases contains 3.4 10-6 mole fraction of radon. This gas at a total pressure of 33 atm is shaken with water at 30°C. Calculate the molar concentration of radon in the water.
Use average bond energies to calculate the energy released when 1 mole of acetylene gas (ethyne, C2H2) reacts completely with O2(g) to form gaseous products. Use the information in the Table of Bond Enthalpies which is in the Chemistry Tables link..
130 mL of an HCl solution with pH of 3.90 is added to 200 mL of an HNO3 solution. The resulting solution is 1.40 mL. What was the pH of the original HNO3 solution?
Find out the molar mass of each of the given gases 1) 2.16 grams of a gas that occupies 1.38L at 665 mmHg
How many millilitres of 0.200 M HCl must be added to 50.0 mL of a 0.200 M solution of NH3 in order to prepare a buffer that has a pH of 8.60? Kb of NH3 = 1.8 x 10-5.
What was the highest alcohol density reported and what was the lowest alcohol density reported by the two students?
Superman flies past you at a speed of 1000 miles/hr. At the moment he passes you, you throw a rock at him at a velocity of 750 meters per second
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd