Functional Group Flashcards: Names & Structures

Cards in this deck

1. Card 1

   Question

   What does a functional group tell you about an organic molecule?

   Answer

   It identifies a characteristic bonding pattern that helps predict chemical behavior. Recognizing the group is a starting point; the rest of the molecule can still affect its reactions.

2. Card 2

   Question

   In the condensed structure CH3–CH(CH3)–CH2–CH3, where does the parenthesized CH3 attach?

   Answer

   To the preceding CH carbon. Parentheses show a branch attached to the atom just before them.

3. Card 3

   Question

   In an organic structural formula, why might two substituents be labeled R and R′?

   Answer

   They stand for groups whose full structures are omitted. The prime distinguishes the two positions; the groups may be the same or different. Check each formula’s definition of R, especially whether H is allowed.

4. Card 4

   Question

   Functional group in CH3–CH=CH–CH3?

   Answer

   Alkene. The defining feature is a carbon–carbon double bond, C=C.

5. Card 5

   Question

   Classify the oxygen-containing functional group in CH3–CH(OH)–CH2–CH3.

   Answer

   Alcohol. The –OH group is attached to a saturated carbon atom.

6. Card 6

   Question

   Functional-group class of CH3–CH(Br)–CH2–CH3?

   Answer

   Haloalkane, also called an alkyl halide. Bromine is bonded directly to a saturated carbon atom.

7. Card 7

   Question

   What bonding unit does C(=O) show in a condensed organic structure?

   Answer

   A carbonyl group: carbon double-bonded to oxygen. The atoms attached to that carbon determine the more specific functional-group class.

8. Card 8

   Question

   Functional group in CH3–O–CH2–CH2–CH3?

   Answer

   Ether. One oxygen links two carbon groups through single bonds, and neither adjacent carbon is a carbonyl carbon.

9. Card 9

   Question

   Functional group in CH3–C≡C–CH2–CH3?

   Answer

   Alkyne. Two carbon atoms are joined by a triple bond.

10. Card 10

    Question

    What does Ph stand for in a condensed organic structure such as Ph–CH2–CH3?

    Answer

    A phenyl group, C6H5–: a benzene ring with one hydrogen replaced by a bond to the rest of the molecule.

11. Card 11

    Question

    Functional group in CH3–CH2–NH–CH3?

    Answer

    Amine. Nitrogen has single bonds to two carbon groups and one hydrogen, making this a secondary amine.

12. Card 12

    Question

    What bond defines an alkene functional group?

    Answer

    A carbon–carbon double bond, C=C, outside an aromatic ring. Carbon–oxygen double bonds belong to a different group family.

13. Card 13

    Question

    What connectivity defines an alcohol group?

    Answer

    An –OH group bonded to a saturated carbon atom. That carbon has only single bonds; an OH directly on a benzene ring is classified separately.

14. Card 14

    Question

    Classify the OH-containing group in Ph–OH, where Ph is a phenyl group (C6H5–).

    Answer

    Phenol. The oxygen of –OH is bonded directly to a carbon in the aromatic ring.

15. Card 15

    Question

    Functional group in CH3–CH2–C≡N?

    Answer

    Nitrile. The carbon chain attaches to the carbon of a carbon–nitrogen triple bond.

16. Card 16

    Question

    What connectivity defines a haloalkane (alkyl halide)?

    Answer

    A halogen bonded directly to a saturated carbon: C–X, where X is F, Cl, Br, or I. The carbon has only single bonds.

17. Card 17

    Question

    A six-carbon ring is drawn with alternating single and double bonds to represent six delocalized π electrons. How is this ring classified?

    Answer

    An aromatic ring: the benzene-ring pattern. Its electrons are delocalized around the ring, so it is not treated as three separate alkene groups.

18. Card 18

    Question

    What connectivity defines a simple ether group?

    Answer

    R–O–R′, with R and R′ attached through carbon and neither attached carbon being a carbonyl carbon. The oxygen has two single bonds and no O–H bond.

19. Card 19

    Question

    Does CH3–CH2–CH2–CH3 contain a characteristic functional group in introductory organic classification?

    Answer

    No. It is an alkane with only C–C and C–H single bonds. Its saturated hydrocarbon framework is the comparison baseline.

20. Card 20

    Question

    What are the three basic connectivity patterns for neutral amines?

    Answer

    R–NH2, R–NH–R′, and R–N(R′)–R″. Here each R is an alkyl or aryl group attached through carbon; the patterns have one, two, or three such groups on nitrogen.

21. Card 21

    Question

    What bond defines an alkyne functional group?

    Answer

    A carbon–carbon triple bond, C≡C. Either end may connect to a carbon group or to hydrogen.

22. Card 22

    Question

    What connectivity defines a phenol group?

    Answer

    An –OH group attached directly to a carbon of an arene ring. In the simplest example, phenol, the structure is C6H5–OH.

23. Card 23

    Question

    What connectivity defines a nitrile group?

    Answer

    R–C≡N, with R attached through carbon. The triple bond joins carbon to nitrogen, and the rest of the molecule attaches on the carbon side.

24. Card 24

    Question

    What ring structure is the standard introductory example of an aromatic group?

    Answer

    A benzene ring: six carbon atoms in a planar ring with six delocalized π electrons. It can be shown as a hexagon with a circle or with alternating single and double bonds.

25. Card 25

    Question

    What single bond-order change distinguishes an alkene group from an alkyne group?

    Answer

    The carbon–carbon bond is double in an alkene and triple in an alkyne: C=C versus C≡C.

26. Card 26

    Question

    Why is Ph–CH2–OH an alcohol, while Ph–OH is a phenol? (Ph = phenyl.)

    Answer

    In Ph–CH2–OH, OH attaches to the saturated CH2 carbon. In Ph–OH, OH attaches directly to the aromatic ring.

27. Card 27

    Question

    Classify the nitrogen group in CH3–N(CH3)–CH2–CH3.

    Answer

    Tertiary amine. Nitrogen has three carbon substituents and no N–H bond; it is still an amine.

28. Card 28

    Question

    Functional group in CH3–CH2–CH2–C(=O)H?

    Answer

    Aldehyde. The carbonyl carbon is bonded to a hydrogen and, here, to a carbon chain.

29. Card 29

    Question

    Functional group in CH3–CH2–C(=O)–O–CH3?

    Answer

    Carboxylic ester. The carbonyl carbon is bonded to an oxygen that also bonds to a non-carbonyl carbon group.

30. Card 30

    Question

    Functional group in CH3–CH2–C(=O)–CH2–CH3?

    Answer

    Ketone. The carbonyl carbon has a carbon atom attached on each side.

31. Card 31

    Question

    Functional group in CH3–CH2–CH2–SH?

    Answer

    Thiol. Sulfur is bonded to a carbon group and to hydrogen.

32. Card 32

    Question

    Functional group in CH3–CH2–C(=O)–NH2?

    Answer

    Amide, specifically a carboxamide. Nitrogen is bonded directly to the carbonyl carbon.

33. Card 33

    Question

    Functional group in CH3–CH2–C(=O)–OH?

    Answer

    Carboxylic acid. An OH group and a double-bonded oxygen attach to the same carbon.

34. Card 34

    Question

    Functional group in CH3–CH2–C(=O)–Cl?

    Answer

    Acid chloride, a carboxylic acid halide (acyl halide). Chlorine is bonded directly to the carbonyl carbon.

35. Card 35

    Question

    Functional group in CH3–CH2–S–CH2–CH2–CH3?

    Answer

    Organic sulfide, also commonly called a thioether. One sulfur links two carbon groups through single bonds.

36. Card 36

    Question

    Functional group in CH3–C(=O)–O–C(=O)–CH2–CH3?

    Answer

    Carboxylic acid anhydride. The central oxygen connects two carbonyl carbons; the carbon groups on the two sides can differ.

37. Card 37

    Question

    What connectivity defines an aldehyde group, including formaldehyde?

    Answer

    R–C(=O)H, where R can be a carbon group or H. The carbonyl carbon has at least one attached hydrogen; formaldehyde is H–C(=O)–H.

38. Card 38

    Question

    What local bonding feature separates a simple ether from a carboxylic ester?

    Answer

    An ester has a carbonyl carbon directly bonded to the linking oxygen: –C(=O)–O–C. A simple ether has C–O–C with neither adjacent carbon being a carbonyl carbon.

39. Card 39

    Question

    Functional group in CH3–CH2–S–S–CH3?

    Answer

    Disulfide. Two sulfur atoms are bonded to each other, with a carbon group at each end.

40. Card 40

    Question

    What connectivity defines a ketone group?

    Answer

    R–C(=O)–R′, with R and R′ both attached through carbon. Neither substituent on the carbonyl carbon is H.

41. Card 41

    Question

    What attachment to nitrogen separates a carboxamide group from an amine group?

    Answer

    A carboxamide’s nitrogen is bonded directly to a carbonyl carbon. An amine’s nitrogen is bonded to alkyl or aryl groups instead of an acyl group.

42. Card 42

    Question

    What connectivity defines a carboxylic acid group?

    Answer

    –C(=O)–OH, the carboxy group. The carbonyl carbon is directly bonded to the oxygen of OH.

43. Card 43

    Question

    What connectivity defines a thiol group?

    Answer

    R–S–H, where R attaches through carbon. The S–H bond is the key recognition cue.

44. Card 44

    Question

    Classify H–C(=O)–H by its carbonyl functional-group family.

    Answer

    Aldehyde. This is formaldehyde (methanal), whose carbonyl carbon has two attached hydrogens.

45. Card 45

    Question

    What connectivity defines a carboxylic ester group?

    Answer

    R–C(=O)–O–R′. Here R is H or a carbon group, and R′ attaches through a non-carbonyl carbon. The linking oxygen has no O–H bond.

46. Card 46

    Question

    What connectivity defines a carboxamide group, including N-substituted forms?

    Answer

    A carbonyl carbon bonded directly to nitrogen: –C(=O)–N. The nitrogen can carry H atoms or carbon substituents; an N–H bond is not required.

47. Card 47

    Question

    What connectivity defines a carboxylic acid halide group?

    Answer

    –C(=O)–X, where X is a halogen attached directly to the carbonyl carbon. For an acid chloride, X is Cl.

48. Card 48

    Question

    What connectivity defines a simple organic sulfide (thioether) group?

    Answer

    R–S–R′, with both groups attached through non-carbonyl carbon atoms. One sulfur bridges the two groups and has no S–H bond.

49. Card 49

    Question

    What connectivity defines a carboxylic acid anhydride group?

    Answer

    –C(=O)–O–C(=O)–: one oxygen links two carbonyl carbons. The groups beyond the carbonyl carbons can be the same or different.

50. Card 50

    Question

    Which attachments to the carbonyl carbon distinguish an aldehyde from a ketone?

    Answer

    An aldehyde has at least one attached H. A ketone has two attached carbon atoms and no H attached to the carbonyl carbon.

51. Card 51

    Question

    Why is the OH in CH3–C(=O)–OH classified as part of a carboxylic acid rather than as an alcohol group?

    Answer

    Its oxygen attaches to a carbonyl carbon. An alcohol’s OH attaches to a saturated carbon; classify the whole –C(=O)–OH unit together.

52. Card 52

    Question

    Which bond at sulfur distinguishes a thiol from a simple organic sulfide?

    Answer

    A thiol has S–H. A simple organic sulfide has sulfur bonded to two carbon groups and no S–H bond.

53. Card 53

    Question

    What connectivity defines an organic disulfide group?

    Answer

    R–S–S–R′, with R and R′ attached through carbon. The central S–S bond distinguishes it from a single-sulfur bridge.

54. Card 54

    Question

    Classify the nitrogen-containing group in CH3–C(=O)–N(CH3)–CH3.

    Answer

    Amide (carboxamide). Nitrogen is directly bonded to the carbonyl carbon, even though it has no N–H bond.

55. Card 55

    Question

    How many carbonyl carbons bond directly to the linking oxygen in a carboxylic ester versus a carboxylic acid anhydride?

    Answer

    One in an ester; two in an anhydride. Follow both bonds from the linking oxygen to check.

56. Card 56

    Question

    How does the carbon bonded to Cl differ in CH3–CH2–Cl and CH3–C(=O)–Cl?

    Answer

    It is a saturated carbon in CH3–CH2–Cl (haloalkane) and a carbonyl carbon in CH3–C(=O)–Cl (acid chloride).

57. Card 57

    Question

    What changes in the bridge between carbon groups when a sulfide is compared with a disulfide?

    Answer

    A sulfide bridge has one sulfur, C–S–C; a disulfide bridge has two, C–S–S–C, including an S–S bond.

57 cards

Functional Group Flashcards: Names & Structures

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