14. Which of the following statements concerning carbocations is false? a) Their
ID: 875399 • Letter: 1
Question
14. Which of the following statements concerning carbocations is false? a) Their relative stability order is 30> 20> 1° b) They can lose a proton from an adjacent C to form an alkene. c) The C has 3 sp3 hybrids and an empty p-orbital and is pyramidal. d) They are trivalent carbon intermediates with a formal "+” charge. d) They are trivalent carbon intermediates with a formal""charge. 15.Which of the following solvents would classified as a polar aprotic solvent (best for.running an Sx2 reaction)2 H2 H2 B) C) D) i ty H3C CXI 16. Which of the following alkyl halides undergoes the slowest solvolysis reaction with methanol, CH3OH (product in each case is tert-butyl methyl ether)? a) tert-butyl bromide b) tert-butyl tosylate c)tert-butyl fluoride d) tert-butyl iodideExplanation / Answer
14. Answer is b) They can lose a proton from adjacent carbon to form alkene.
They loose a proton to form positively charged carbocation.
15. Answer is b) ethane amide
Reason: Polar protic solvent will form hydrogen bond with nucleophile hindering it to attack the carbon with leaving group. A polar aprotic solvent with low dieklectric constant favours SN2 reaction.
16.Answer is c) tert-butyl fluoride
As the alkylfluorides are most stable
17. Answer is C) as in this reaction Br is substituted by OH- group. so called as substitution reaction.
18. Answer is c)
the nucleophile attacks the substrate from the opposite side of the leaving group in Sn2 reaction, In the transition state, the nucleophile-carbon bond is partially cleaved, while the nucleophile-carbon bond is partially formed. The transition state is characterised by increase in energy and is short lived and then finally energy drop down to form the product.