Question

ASAP need help with 1 to 10 please and thank you

1. Multiple choice questions (20) 1.Which of the followings is the most reactive one in electrophilic aromatic substitution? NO; D. A. B 2. If a proton resonance at 200 MHz in a spectrometer with a magnetic field of 4.7 T, what will be its resonance frequency in a spectrometer with a magnetic field of 9.4 T? A. 200 MHz B. 400 MHz C. 800 MHz D. 100 MHz ) 3. In which of following compounds carbon-hydrogen bond shows the highest stretching vibration frequency in its IR spectrum? A. Ethane ( D. Methane C. Ethyne B. Ethene ) 4. Which of the following compounds possesses the most deshielded proton? A. Ethane D. Ethyne B. Methane C. Ethene )5. Which of the following compounds has its max at the longest wavelength? ( C. D. B. 6. Which of following statements about electrophilic aromatic substitution (EAS) mechanism is correct? A. In an EAS reaction, an elimination step follows an electrophilic addition step B. In a EAS reaction, an electronphilic addition follows an elimination step C. EAS follows SN2 mechansim D. EAS follows Syl mechanism ( ) 7. The chemical shift of one proton is 6.5 ppm on a 200 MHz spectrometer, what will be its chemical shift on a 400 MHz spectrometer? A. 13 ppm D. 6.5 ppm B. 3.25 ppm C. 26 ppm (HC)8. Which of the following statements on 'H and'C NMR is correct? A. H NMR offers better resolution B. C NMR offers better resolution C. 'H NMR is less sensitive D. The intensity ratio of two C NMR peaks is equal to the ratio of corresponding C nuclei that produce the signals ( )9. In which of the following compounds the proton is most shielded? A. CHCI D. CH2C B.CH C. CH CI ) 10. What is the base peak (m/Z) in the mass spectrum of toluene? C. 119 ( D. 91 B. 105 A. 77

Answer 1

1. Option D, since OMe is strong Electron donating group

2. Option B,

3. Option C, in alkyne

4. Option D, alkyne proton

5. Option A, since it has more conjugation which increases the wavelength.

6.: option B

7. Option D, no change in chemical shifts

8. Option A

9. Option A, more the EWG group more the a desheild

10. Option A ,@77