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12 Nov 2019
Are these right? CHE 204 Exam 2 Practice Exam Multiple choice: Select the best answer for each question below 2. Which of the following gives rise to a prominent M- 18 peak in the mass spectrum? a. eyclohexane b. cyclohexene 1-chlorocyclohexane 3. Which of the following sets of molecular ions does an alkyl bromide possess? a two molecular ions in a 2:I ratio separated by two mass units b.) two molecular ions in a 1:1 ratio separated by two mass units c. three molecular ions in a 1:2:1 ratio separated by two mass units d. two molecular ions in a 3:1 ratio separated by two mass units 4. Which of the following is the definition of the base peak of a mass spectrum? a.) the peak corresponding to the most abundant ion the peak corresponding to the ion with lowest me c. the peak corresponding to the molecular ion peak d. the peak corresponding to the ion arising to loss of a proton from the molecular ion 5. Which feature in the 'H NMR spectrum provides information about the electronic number of signals b) integnal chemical shift 6. Which of the following combinations of peaks appears in the 'HNMR spectrum of diethyl environment of the protons in a compound? ether, CH CH OCH CH? c) two singlets a triplet and a doublet a quartet and a sextet a. b. a triplet and a quartet 7. How many signals appear in proton-decoupled "'C NMR spectrum of 2,3-dimethylhexane? a) 3 4 c) 5 8. Which of the following is not true about the Wittig reaction? triphenylphosphine reacts with 1° alkyl bromides by an Sy2 reaction to give an alkyltriphenylphosphonium bromide alkyltriphenylphosphonium bromides are deprotonated by strong bases to give a phosphonium ylide phosphonium ylides are nucleophilic the product of the Wittig reaction is an alcohol a. b.
Are these right?
CHE 204 Exam 2 Practice Exam Multiple choice: Select the best answer for each question below 2. Which of the following gives rise to a prominent M- 18 peak in the mass spectrum? a. eyclohexane b. cyclohexene 1-chlorocyclohexane 3. Which of the following sets of molecular ions does an alkyl bromide possess? a two molecular ions in a 2:I ratio separated by two mass units b.) two molecular ions in a 1:1 ratio separated by two mass units c. three molecular ions in a 1:2:1 ratio separated by two mass units d. two molecular ions in a 3:1 ratio separated by two mass units 4. Which of the following is the definition of the base peak of a mass spectrum? a.) the peak corresponding to the most abundant ion the peak corresponding to the ion with lowest me c. the peak corresponding to the molecular ion peak d. the peak corresponding to the ion arising to loss of a proton from the molecular ion 5. Which feature in the 'H NMR spectrum provides information about the electronic number of signals b) integnal chemical shift 6. Which of the following combinations of peaks appears in the 'HNMR spectrum of diethyl environment of the protons in a compound? ether, CH CH OCH CH? c) two singlets a triplet and a doublet a quartet and a sextet a. b. a triplet and a quartet 7. How many signals appear in proton-decoupled "'C NMR spectrum of 2,3-dimethylhexane? a) 3 4 c) 5 8. Which of the following is not true about the Wittig reaction? triphenylphosphine reacts with 1° alkyl bromides by an Sy2 reaction to give an alkyltriphenylphosphonium bromide alkyltriphenylphosphonium bromides are deprotonated by strong bases to give a phosphonium ylide phosphonium ylides are nucleophilic the product of the Wittig reaction is an alcohol a. b.
Jean KeelingLv2
16 Apr 2019