BIOB111_CHBIO - Tutorial activities for session 9

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1 BIOB111_CHBIO - Tutorial activities for session 9 General topics for week 5 Session 9 Physical properties and chemical reactions of organic compounds (functional groups: alcohols, phenols, ethers, aldehydes, ketones, carboxylic acids thiols) Examples of compounds containing these functional groups Tutorial questions: Alcohols 1. Concept: Atoms that make up the alcohol functional group Context: Drinking alcohol usually contains between 2 and 50% ethanol. Ethanol belongs to the alcohol family of compounds, as it contains the alcohol functional group. Question: Which of the following atom sets is characteristic of the alcohol functional group (aka the hydroxyl group)? a) R-NH 2 b) R-CHO c) R-CO-R d) R-OH 2. Concept: Identifying the alcohol functional group from a structure looking at the compounds chemical structure, as particular sets of atoms represent the different functional groups. Question: Which of the compounds below possesses the alcohol functional group (aka the hydroxyl group)? a) CH 3 CH 2 CH 2 OH b) CH 3 O CH 3 c) d) CH 3 CH 2 SH 3. Concept: Identifying the alcohol functional group from a compound name Last Updated on6-feb-14 Page 1 of 16

2 looking at the name of the compound, as each functional group specifies a particular naming method, often with certain letters at the end of the compound name. Question: Which of the compounds below possesses the alcohol functional group (aka the hydroxyl group)? a) Propanone b) Ethanoic acid (acetate/acetic acid) c) Butanal d) Propanol 4. Concept: Position of the alcohol functional group in a compound Context: Functional groups can be present in one of two locations within a compound. The functional group can exist in the middle of a compound between two carbon chains, or the functional group can be present at the end of a compound, only connecting to one carbon chain. The number of R groups (sets of atoms) that a functional group contains tells you how many carbon chains the functional group is capable of connecting to. Question: Where is the alcohol functional group located within a compound and for what reason? a) The functional group connects to one R group, meaning the functional group will b) The functional group connects to two R groups, meaning the functional group will c) The functional group connects to two R groups, meaning the functional group will d) The functional group connects to one R group, meaning the functional group will 5. When alcohol is ingested from an alcoholic beverage, the ethanol within the alcohol will eventually be taken to the liver to be broken down into less toxic compound via oxidation so that it can be further metabolised. The breakdown of alcohol in the liver relies on redox reactions, where one reactant is oxidised and the other is reduced. Which of the following best describes the breakdown on alcohol in the liver? Last Updated on6-feb-14 Page 2 of 16

3 a) The toxic ethanol is first oxidised to acetaldehyde before a second oxidation to acetate, both of which occur in the blood b) The non-toxic ethanol is first reduced to acetaldehyde before a second reduction to acetate, both of which occur in the liver c) The non-toxic ethanol is first reduced to acetaldehyde before a second reduction to acetate, both of which occur in the blood d) The toxic ethanol is first oxidised to acetaldehyde before a second oxidation to acetate, both of which occur in the liver 6. Concept: Identifying primary, secondary and tertiary alcohols Context: Compounds that contain a single alcohol group, can be divided into the primary, secondary and tertiary alcohols. The number of carbons directly bonded to the carbon attached to the alcohol functional group (aka hydroxyl group) specifies which of these groups the compound belongs to. Question: Which of the following compounds is a secondary alcohol? a) b) c) d) Tutorial questions: Phenols 7. Concept: Atoms that make up the phenol functional group Context: Phenol it s self is toxic to the liver, but derivatives of phenol that contain other atoms are useful as antiseptics such as mouth washes. Last Updated on6-feb-14 Page 3 of 16

4 Question: Which of the following atom sets is characteristic of the phenol functional group? a) R-O-R b) R-OH c) Benzene ring-oh d) R-CHO 8. Concept: Identifying the phenol functional group from a structure looking at the compounds chemical structure, as particular sets of atoms represent the different functional groups. Question: Which of the compounds below possesses the phenol functional group? a) b) CH 3 CH 2 CH 2 OH c) d) 9. Concept: Identifying the phenol functional group from a compound name looking at the name of the compound, as each functional group specifies a particular naming method, often with certain letters at the end of the compound name. Question: Which of the compounds below possesses the phenol functional group? a) Propanal b) Butanoic acid c) Ethanol d) 4-chlorophenol 10. Concept: Phenol groups contribution to antioxidants Last Updated on6-feb-14 Page 4 of 16

5 Context: Vitamin E contains a phenol derivative and has a major role in our body as an antioxidant. It is important that we maintain high levels of antioxidants in our body to prevent oxidative damage by reactive oxygen species that can damage parts of our cells. Question: How do antioxidants prevent free radicals from damaging cells? a) Antioxidants prevent all redox reactions from occurring in cells, so that no oxidative damage occurs b) Antioxidants will be oxidised by reactive oxygen species by participating in redox reactions, to prevent part of the cell taking on oxidative damage c) Antioxidants will be reduced by reactive oxygen species by participating in redox reactions, which will cause damage to the cell d) Antioxidants do not prevent redox reactions from occurring in cells, but are required for mitochondria to function correctly Tutorial questions: Ethers 11. Concept: Atoms that make up the ether functional group Context: In the past, ethers were used as anaesthetics which inhibited pain signals, although they did have some side effects including nausea. The newer halogenated ethers (that include chlorine and fluorine atoms) that are used today have much fewer side effects. Question: Which of the following atom sets is characteristic of the ether functional group? a) R-COO-R b) R-OH c) R-O-R d) R-NH Concept: Identifying the ether functional group from a structure looking at the compounds chemical structure, as particular sets of atoms represent the different functional groups. Question: Which of the compounds below possesses the ether functional group? a) CH 3 CH 2 CH 2 SH Last Updated on6-feb-14 Page 5 of 16

6 b) CH 3 O CH 3 c) d) 13. Concept: Identifying the ether functional group from a compound name looking at the name of the compound, as each functional group specifies a particular naming method, often with certain letters at the end of the compound name. Question: Which of the compounds below possesses the ether functional group? a) Methanethiol b) Methoxyethane c) Ethyl butanoate d) Propanamide 14. Concept: Position of the ether functional group in a compound Context: Functional groups can be present in one of two locations within a compound. The functional group can exist in the middle of a compound between two carbon chains, or the functional group can be present at the end of a compound, only connecting to one carbon chain. The number of R groups (sets of atoms) that a functional group contains tells you how many carbon chains the functional group is capable of connecting to. Question: Where is the ether functional group located within a compound and for what reason? a) The functional group connects to two R groups, meaning the functional group will b) The functional group connects to two R groups, meaning the functional group will c) The functional group connects to one R group, meaning the functional group will d) The functional group connects to one R group, meaning the functional group will Last Updated on6-feb-14 Page 6 of 16

7 15. Concept: Atoms are neutral Context: Ethers have the useful property of being unreactive towards acids, bases and oxidising agents (e.g. reactive oxygen species). Ethers are also good as organic solvents, which can dissolve non-polar compounds. Question: Which of the following would an ether be useful for? a) An ether is a polar solvent so it can dissolve polar substances such different salts e.g. NaCl b) An ether is a non-polar solvent so it can dissolve non-polar substances such as fats and waxes c) An ether is a non-polar solvent so it can dissolve polar substances such different salts e.g. NaCl d) An ether is a polar solvent so it can dissolve non-polar substances such as fats and waxes Tutorial questions: Thiols 16. Concept: Atoms that make up the thiol functional group Context: Compounds that contain the thiol group usually have strong sometimes disagreeable odours. For example, skunk essence is contains two different thiol compounds. Question: Which of the following atom sets is characteristic of the thiol functional group (aka sulfhydryl group)? a) R-CO-R b) R-SH c) R-NH 2 d) R-OH 17. Concept: Identifying the thiol functional group from a structure looking at the compounds chemical structure, as particular sets of atoms represent the different functional groups. Last Updated on6-feb-14 Page 7 of 16

8 Question: Which of the compounds below possesses the thiol functional group (aka sulfhydryl group)? a) CH 3 CH 2 CH 2 OH b) c) CH3 CH2 CH2 SH d) 18. Concept: Identifying the thiol functional group from a compound name looking at the name of the compound, as each functional group specifies a particular naming method, often with certain letters at the end of the compound name. Question: Which of the compounds below possesses the thiol functional group (aka sulfhydryl group)? a) Ethanethiol b) Propanol c) Propanamine d) Ethanamide 19. Concept: Position of the thiol functional group in a compound Context: Functional groups can be present in one of two locations within a compound. The functional group can exist in the middle of a compound between two carbon chains, or the functional group can be present at the end of a compound, only connecting to one carbon chain. The number of R groups (sets of atoms) that a functional group contains tells you how many carbon chains the functional group is capable of connecting to. Question: Where is the thiol functional group located within a compound and for what reason? a) The functional group connects to two R groups, meaning the functional group will b) The functional group connects to one R group, meaning the functional group will Last Updated on6-feb-14 Page 8 of 16

9 c) The functional group connects to two R groups, meaning the functional group will d) The functional group connects to one R group, meaning the functional group will 20. Concept: Disulfide bonding by thiols Context: Two thiol functional groups can connect together to form a disulfide attachment. The disulfide is a strong covalent attachment between two separate thiol groups. Question: What must happen to each of the thiol functional groups so that they can together form the disulfide bond (link)? a) Before the disulfide is formed, each of the thiol functional groups must be lost from the compounds b) Each of the individual thiol groups must lose its hydrogen via oxidation, which allows the two remaining sulfur atoms (within the thiol group) to form a covalent bond, which creates the disulfide c) The sulfur atoms must detach from the compounds before they can be incorporated into the disulfide d) Each of the thiol groups must first gain a hydrogen atom via a reduction reaction, only then can the two sulfur atoms within the thiol group form a covalent attachment to each other, which forms the disulfide Tutorial questions: Aldehydes 21. Concept: Atoms that make up the aldehyde functional group Context: The simplest aldehyde is methanal (aka formaldehyde) is often mixed with water to produce a solution called formalin. Formalin is often used for persevering biological specimens including cadavers. Question: Which of the following atom sets is characteristic of the aldehyde functional group? a) R-CO-R b) R-OH c) R-CHO Last Updated on6-feb-14 Page 9 of 16

10 d) R-COOH 22. Concept: Identifying the aldehyde functional group from a structure looking at the compounds chemical structure, as particular sets of atoms represent the different functional groups. Question: Which of the compounds below possesses the aldehyde functional group? a) CH 3 CH 2 CH 2 OH b) c) d) 23. Concept: Identifying the aldehyde functional group from a compound name looking at the name of the compound, as each functional group specifies a particular naming method, often with certain letters at the end of the compound name. Question: Which of the compounds below possesses the aldehyde functional group? a) Pentanone b) Propanal c) Ethoxybutane d) Butanonic acid 24. Concept: Position of the aldehyde functional group in a compound Context: Functional groups can be present in one of two locations within a compound. The functional group can exist in the middle of a compound between two carbon chains, or the functional group can be present at the end of a compound, only connecting to one carbon chain. The number of R groups (sets of atoms) that a functional group contains tells you how many carbon chains the functional group is capable of connecting to. Last Updated on6-feb-14 Page 10 of 16

11 Question: Where is the aldehyde functional group located within a compound and for what reason? a) The functional group connects to two R groups, meaning the functional group will b) The functional group connects to two R groups, meaning the functional group will c) The functional group connects to one R group, meaning the functional group will d) The functional group connects to one R group, meaning the functional group will 25. Concept: Oxidation of aldehydes Context: Aldehyde compounds can participate in redox reactions. In a redox reaction one of the reactants is oxidised and the other is reduced. In a redox reaction, the aldehyde functional group is oxidised to the carboxylic acid functional group by accepting an additional hydroxyl group (OH) in place of the hydrogen atom. Question: Which of the following represents the functional group change when an aldehyde is oxidised to a carboxylic acid? a) >>>> converted to >>>> b) >>>> converted to >>>> c) >>>> converted to >>>> d) >>>> converted to >>>> Tutorial questions: Ketones 26. Concept: Atoms that make up the ketone functional group Last Updated on6-feb-14 Page 11 of 16

12 Context: One of the most common ketones is propanone (more commonly known as acetone), a non-polar organic solvents that is present in nail polish remover. Organic solvents are able to dissolve non-polar substances such as fats and oils. Question: Which of the following atom sets is characteristic of the ketone functional group? a) R-COOH b) R-CHO c) R-OH d) R-CO-R 27. Concept: Identifying the ketone functional group from a structure looking at the compounds chemical structure, as particular sets of atoms represent the different functional groups. Question: Which of the compounds below possesses the ketone functional group? a) b) c) d) CH 3 CH 2 CH 2 OH 28. Concept: Identifying the ketone functional group from a compound name looking at the name of the compound, as each functional group specifies a particular naming method, often with certain letters at the end of the compound name. Question: Which of the compounds below possesses the ketone functional group? a) Metanol b) Ethanamide c) Pentanone Last Updated on6-feb-14 Page 12 of 16

13 d) Butanethiol 29. Concept: Position of the ketone functional group in a compound Context: Functional groups can be present in one of two locations within a compound. The functional group can exist in the middle of a compound between two carbon chains, or the functional group can be present at the end of a compound, only connecting to one carbon chain. The number of R groups (sets of atoms) that a functional group contains tells you how many carbon chains the functional group is capable of connecting to. Question: Where is the ketone functional group located within a compound and for what reason? a) The functional group connects to two R groups, meaning the functional group will b) The functional group connects to two R groups, meaning the functional group will c) The functional group connects to one R group, meaning the functional group will d) The functional group connects to one R group, meaning the functional group will 30. Concept: Ketones resist oxidation Context: In comparison to aldehyde which are readily oxidised in redox reactions (to carboxylic acids), ketones are able to resist oxidation. The ketones capacity to resist oxidation means that they are considered less reactive than aldehydes. Question: Which of the following best explains why ketones do not participate in redox reactions? a) The carbonyl group (C=O) is attached to two carbon chains, so there are no atoms that are available to participate in a redox reaction to take on an additional oxygen atom b) The ketone is always reduced in a redox reaction, rather than being oxidised, meaning ketones are able to resist oxidation a) The carbonyl group (C=O) is attached to one carbon chain, so there is a hydrogen atom available to participate in a redox reactions Last Updated on6-feb-14 Page 13 of 16

14 d) The ketone is always oxidised in a redox reaction, rather than being reduced, meaning ketones are able to resist reduction Tutorial questions: Carboxylic acids 31. Concept: Atoms that make up the carboxylic acid functional group Context: Compounds that contain the carboxylic acid functional group, are acidic as their name suggests. As an acid they are capable of donating their H + to a base or into solution. Question: Which of the following atom sets is characteristic of the carboxylic acid functional group (aka carboxyl group)? a) R-OH b) R-COOH c) R-O-R d) R-COO-R 32. Concept: Identifying the carboxylic acid functional group from a structure looking at the compounds chemical structure, as particular sets of atoms represent the different functional groups. Question: Which of the compounds below possesses the carboxylic acid functional group (aka carboxyl group)? a) CH3 O CH3 b) c) d) 33. Concept: Identifying the carboxylic acid functional group from a compound name Last Updated on6-feb-14 Page 14 of 16

15 looking at the name of the compound, as each functional group specifies a particular naming method, often with certain letters at the end of the compound name. Question: Which of the compounds below possesses the carboxylic acid functional group (aka carboxyl group)? a) Methanol b) Metyl propanoate c) Butanone d) Pentanoic acid 34. Concept: Position of the carboxylic acid functional group in a compound Context: Functional groups can be present in one of two locations within a compound. The functional group can exist in the middle of a compound between two carbon chains, or the functional group can be present at the end of a compound, only connecting to one carbon chain. The number of R groups (sets of atoms) that a functional group contains tells you how many carbon chains the functional group is capable of connecting to. Question: Where is the carboxylic acid functional group located within a compound and for what reason? a) The functional group connects to one R group, meaning the functional group will b) The functional group connects to two R groups, meaning the functional group will c) The functional group connects to two R groups, meaning the functional group will d) The functional group connects to one R group, meaning the functional group will 35. Concept: Carboxylic acids behave like an acid Context: As their name suggests, carboxylic acids are acids. Carboxylic acids are classed as weak acids, meaning they retain their H + the majority of the time. Question: How is the carboxylic acid functional group altered after donating its H + to a base? Last Updated on6-feb-14 Page 15 of 16

16 a) Before donating its H +, the carboxylic acid is in the form of R-COO -, but after the carboxylic acid donates its H + to a base, the carboxylic acid is in the form of R-COOH b) The carboxylic acid functional group is in the form of R-COO -, before and after the carboxylic acid donates its H + to a base c) Before donating its H +, the carboxylic acid is in the form of R-COOH, but after the carboxylic acid donates its H + to a base, the carboxylic acid is in the form of R-COO - d) The carboxylic acid functional group is in the form of R-COOH, before and after the carboxylic acid donates its H + to a base Last Updated on6-feb-14 Page 16 of 16

BIOB111_CHBIO - Tutorial activity for Session 10. Conceptual multiple choice questions:

BIOB111_CHBIO - Tutorial activity for Session 10 General Topics for Session 10 Week 5 Properties of the functional groups and examples. Amines, amides and Esters Physical properties and chemical reactions: