Question
please please answer all if the questions!!!!! pleaseeeee
Spring 2015 February 25, 2015 CHM 256 Examination I First Name: Last Name: Left-hand neighbor: I. Multiple choices and blank fill-ins (Each entry 3 pts, 48 pts) 1. Which of the following functional group exhibits the lowest stretching vibration frequency? Right-hand neighbor A)C-S B). C-O 2. The functional group(s) that you can identify in the following IR spectrum is (are) (and) (up to two functional groups) 100 60 40 20 3500 3000 2500 2000 1500 1000 500 Wavenumbers, em 3. Which of the followings is the most reactive one in electrophilic aromatic substitution? 4. If a proton resonance at 200 MHz in a spectrometer with a magnetic field of 4.7 T, the resonance frequency in a spectrometer with a magnetic field of 9.4 T is 5. In which of following compounds carbon-hydrogen bond shows the highest stretching vibration frequency in its IR spectrum? A. Ethane B. Ethene C. Ethyne D. Methane 6, which ofthe following compounds possesses the most deshielded (largest ) proton? A. Ethane B. Methane C. Ethene D. Propane 7. Which of the following compounds has its 2max at the longest wavelength? 8. 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
Explanation / Answer
since you posted several questions i will give onyl answers not explanation
1. D
2. C-H and C=O
3. D
4. 400 MHz
5. C around 3333 cm-1
6. C
7. A
8. B
