Propene, C₃H₆, reacts with H₂O in the presence of an acid catalyst to form an alcohol with molecular formula C₃H₈O.
- (a)Name this type of reaction.[1]
- (b)Name the catalyst used and state the conditions needed for this reaction to occur. catalyst conditions[2]
- (c)Complete the table to show the numbers of sigma (σ) bonds and pi (π) bonds present in propene, C₃H₆, and C₃H₈O. C₃H₆ C₃H₈O σ π[2]
- (d)(i)The reaction of propene, C₃H₆, with H₂O occurs in a two-step mechanism. In step 1 C₃H₆ reacts with the catalyst, H⁺, to form a carbocation. Draw structures to identify the more stable and less stable carbocations which can form in step 1. Explain your answer. more stable carbocation less stable carbocation explanation[3]
- (d)(ii)Name the major organic product formed from the reaction of propene, C₃H₆, with H₂O.[1]
- (e)(i)2-bromopropane reacts to form propene, hydrogen bromide and water under certain conditions. Name this type of reaction.[1]
- (e)(ii)Describe the reagents and conditions needed to favour this reaction. reagents conditions[2]
Mark scheme
Marking points from the official mark scheme (May/June 2021). The mark or mark type is shown in brackets.
- [1] addition
- [1] M1 catalyst = sulfuric acid / phosphoric(V) acid
- [1] M2 conditions of reaction = steam / heat (and pressure)
- [2] σ π C3H6 8 1 C3H8O 11 0
- [1] M1 more stable = CH3C+(H)(CH3)
- [1] M2 less stable = CH3CH2C+(H2) /
- [1] M3 greater (positive) inductive effect of two alkyl groups OR greater electron donation of two alkyl groups owtte
- [1] propan-2-ol
- [1] elimination
- [1] M1 NaOH/KOH
- [1] M2 ethanolic solution / ethanol / alcohol + heat
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →