NMR

• TCDD can also be analysed using 13C n.m.r. 4 (d) (i) Give the formula of the compound used as the standard when recording a 13C spectrum

  Si(CH3)4 TMS
• The 1 H n.m.r. spectrum was recorded using a solution of atenolol in CDCl3

  Suggest why CDCl3 and not CHCl3 was used as the solvent.

  
  

  Solvent must be proton-free OR CHCl3 has protons or has H or gives a peak
• Suggest why CDCl3 is a more effective solvent than CCl4 for polar molecules such as atenolol.

  CDCl3 is polar OR CCl4 is non-polar
• Give two other reasons why TMS is used as a standard in recording n.m.r. spectra

  Single/one (intense) peak/signal

  Low bp OR volatile