Alcohols and Carboxylic Acids Ws

1 Name:______________________________( ) Class:_________ Date:___________ AFL Worksheet Alcohols and Carboxylic Acids Multiple-Choice Questions (10 marks) 1. Ethanol can be produced from ethene by __________. A addition B oxidation C reduction D substitution ( ) 2. Fermentation occurs when yeast is added to sugar solution. Which of these changes would speed up the fermentation process? A Increasing the temperature above 35°C B Placing the fermenting flask in boiling water C Using distilled water when making the sugar solution D Making the sugar solution more concentrated ( ) 3. An alcohol contains 50% by mass of oxygen. Which of these alcohols could it be? A Butanol B Ethanol C Methanol D Propanol ( ) 4. Which of the following substances could be a carboxylic acid? A CH 2O B CH2O2 C C 2H3O2 D C 2H4O2 ( ) 5. Which of the following reactions does not produce water? A Combustion of ethanol B Fermentation of glucose C Reaction of ethanoic acid with sodium carbonate D Oxidation of ethanol to ethanoic acid ( ) 25

2 6. An organic compound, Y, has the following structural formula. Which of the following statements about Y is not correct? A It changes red litmus to blue. B It is an unsaturated compound. C It has a relative molecular mass of 86. D It decolourises aqueous bromine. ( ) 7. Which of these statements are true about carboxylic acids? 1 They react with magnesium to produce oxygen gas. 2 They are fully ionised in solution. 3 They neutralise bases to form a salt and water. 4 They give off carbon dioxide gas when added to carbonates. A 1, 2 and 3 B 2, 3 and 4 C 3 and 4 D 1, 2, 3 and 4 ( ) 8. Ethanol is oxidised when it is heated with acidified potassium manganate(VII) solution. What colour change is observed? A Colourless to purple B Purple to colourless C Orange to green D Reddish-brown to colourless ( ) 9. An ester is formed by warming an alcohol with a carboxylic acid. A few drops of concentrated sulfuric acid are also added. What is the purpose of adding sulfuric acid? A To catalyse the reaction B To increase the yield of the ester C To neutralise any excess alcohol D To slow down the evaporation of reactants and products ( ) C C OH H H H C C H H O

3 10. What is the product formed when propanol, CH3CH2CH2OH, reacts with ethanoic acid, CH3COOH? A CH 3COOCH2CH2CH3 B CH 3CH2CH2COOCH3 C CH 3CH2COOCH2CH3 D CH 3COOCH2CH3 ( ) Structured Questions (15 marks) 11. Consider the following four compounds: CH3CH=CH2 CH3COOH CH3CH2OH CH3COOC2H5 P Q R S State the compound which (a) has the empirical formula CH2O; [1] (b) reacts with acidified potassium manganate(VII); [1] (c) has a sweet and pleasant smell; [1] (d) decolourises bromine water; [1] (e) produces hydrogen when reacted with metals. [1] 12. A fermenting flask or a demijohn is shown below. It is used in the fermentation of sugars during wine making. (a) (i) What is the gas given off during the fermentation process? [1] air air lock fermenting jar fermenting mixture

4 (ii) Describe how this gas may be identified. [1] (b) Why is it important to prevent air from entering the flask? [1] (c) Why does the fermentation process gradually stop when the temperature is raised above 35°C? [1] (d) State how pure ethanol is obtained from the fermentation process. [1] 13. An organic compound, Z, has the structural formula CH3CH2COOC2H5. (a) (i) Describe how Z can be produced and name the reaction involved. [3] (ii) Write a chemical equation for the reaction in (i). [1] (b) Identify the organic compound Z. [1]