Alcohols & Phenol Chemistry Questions PDF

1. Which of the following is the general formula for a primary alcohol? * A) RCH2OH * B) R2CHOH * C) R3COH * D) ROH 2. What is the product formed when a primary alcohol is oxidised using acidi ed potassium dic...

1. Which of the following is the general formula for a primary alcohol? * A) RCH2OH * B) R2CHOH * C) R3COH * D) ROH 2. What is the product formed when a primary alcohol is oxidised using acidi ed potassium dichromate(VI)? * A) A ketone * B) An aldehyde, and then a carboxylic acid * C) An alkene * D) An ester 3. What is the colour change observed when potassium dichromate(VI) oxidises an alcohol? * A) Purple to colourless * B) Orange to green * C) Colourless to orange * D) Green to orange 4. What is the product when a secondary alcohol is oxidised? * A) Aldehyde * B) Ketone * C) Carboxylic Acid * D) No Reaction 5. Which of the following reagents can be used to distinguish between a primary and tertiary alcohol? * A) Concentrated sulfuric acid * B) Acidi ed potassium manganate(VII) * C) Sodium hydroxide * D) 2,4-dinitrophenylhydrazine 6. What conditions are required for the dehydration of an alcohol to form an alkene? * A) Re ux with concentrated H2SO4 * B) Re ux with dilute H2SO4 * C) Re ux with acidi ed K2Cr2O7 * D) Re ux with acidi ed KMnO4 fi fl fl fl fl fi fi fi 7. Which of the following equations correctly represents the dehydration of ethanol? * A) CH3CH2OH → CH3CHO + H2 * B) CH3CH2OH → CH2=CH2 + H2O * C) 2CH3CH2OH → CH3CH2OCH2CH3 + H2O * D) CH3CH2OH + [O] → CH3COOH +H2O 8. What is the product when a primary alcohol reacts with PCl5? * A) Haloalkane * B) Alkene * C) Ester * D) Carboxylic Acid 9. What is the product when a primary alcohol reacts with a carboxylic acid? * A) Haloalkane * B) Alkene * C) Ester * D) Ketone 10. Which of the following is the correct equation for the reaction of ethanol with sodium? * A) 2CH3CH2OH + 2Na → 2CH3CH2ONa + H2 * B) CH3CH2OH + Na → CH3CH2Na + OH * C) CH3CH2OH + NaOH → CH3CH2ONa + H2O * D) CH3CH2OH + Na → CH3CH2ONa + 1/2 H 11. What observations would show a positive result for an alcohol reacting with sodium? * A) Effervescence and the solid dissolves. * B) A white precipitate forms. * C) A silver mirror forms. * D) The solution turns from orange to green. 12. Which is more acidic, phenol or ethanol? * A) Ethanol * B) Phenol * C) They have the same acidity * D) Not enough information provided 13. What is formed when phenol reacts with sodium hydroxide? * A) Sodium Phenoxide and Hydrogen Gas * B) Sodium Phenoxide and water * C) Benzene and water * D) No Reaction 14. What is formed when phenol reacts with bromine water? * A) 2-bromophenol * B) 2,4,6-tribromophenol * C) Bromobenzene * D) 4-bromophenol 15. What observation is associated with a positive result for the reaction between phenol and bromine water? * A) The bromine water is decolorised and a white precipitate forms. * B) The bromine water changes from colourless to orange. * C) Effervescence is produced. * D) No visible reaction. 16. Why is phenol more reactive than benzene? * A) The OH group is electron withdrawing. * B) The lone pair on the oxygen overlaps with the delocalised pi system. * C) Phenol is smaller than benzene. * D) Phenol does not have a delocalised pi system. 17. Which of the following is NOT a reaction of phenol? * A) With sodium hydroxide * B) With sodium  * C) With bromine * D) With potassium dichromate(VII) 18. What is the correct equation for the reaction between phenol and sodium? * A) C6H5OH + Na → C6H5ONa + ½ H2 * B) C6H5OH + Na → C6H5Na + ½ H2O * C) C6H5OH + NaOH → C6H5ONa + H2O * D) C6H5OH + Na → C6H6 + NaOH 19. How does the -OH group affect the positions at which substitution occurs on the benzene ring in phenol? * A) It directs to positions 2, 4, and 6. * B) It directs to positions 3 and 5. * C) It directs to position 4 only. * D) It does not affect the position of substitution. 20. Which of the following is a suitable reagent and conditions for dehydrating an alcohol? * A) Re ux with acidi ed potassium manganate(VII) * B) Re ux with conc. H2SO4 * C) Re ux with dilute H2SO4 * D) Re ux with PCl5 Answers and Explanations: 1. A - RCH2OH (The carbon bonded to the -OH is bonded to only one other carbon). 2. B - First to an aldehyde, then further oxidation to a carboxylic acid. 3. B - Dichromate(VI) (Cr2O72-) is reduced (orange to green). 4. B 5. B - Acidi ed potassium manganate(VII) will oxidise primary and secondary, but not tertiary. 6. A 7. B - Dehydration removes water, forming the alkene. 8. A fl fl fl fl fi fi 9. C 10. A - Sodium replaces the H in the -OH group, forming the alkoxide and hydrogen gas. 11. A 12. B - The phenoxide ion is stabilised by delocalisation of the negative charge. 13. B 14. B 15. A 16. B 17. D Phenol cannot be oxidised by potassium dichromate(VII). 18. A 19. A - The -OH group is 2,4,6-directing. 20. B