chemistry: chapter 16, pt. 2

Introduction to Alkanes

• Alkanes are saturated hydrocarbons characterized by C-C single bonds.

Carbon Chain Length Indicators

• Stems indicating the length of the main carbon chain:

  • meth-: 1 carbon

  • eth-: 2 carbons

  • prop-: 3 carbons

  • but-: 4 carbons

  • pent-: 5 carbons

  • hex-: 6 carbons

  • hept-: 7 carbons

  • oct-: 8 carbons

  • non-: 9 carbons

  • dec-: 10 carbons

Determining Hydrogen Count in Alkanes

Linear Alkanes

• Formula: C_nH_(2n+2) where n = number of carbon atoms.

  • Example:

    • For 8 carbons (C8): H = 2(8)+2 = 18 (C8H18)

Cycloalkanes

• Formula: C_nH_(2n) where n = number of carbon atoms.

  • Example:

    • For 12 carbons (C12): H = 2(12) = 24 (C12H24)

Practice Questions

Question 1

• Which element can form stable covalent bonds with itself and others?

  • a. Hydrogen

  • b. Carbon (correct answer)

Question 2

• What are hydrocarbons with C-C bonds in a chain?

  • d. Alkanes (correct answer)

Question 3

• Identify the substance with the molecular formula C7H16.

  • b. Heptane (correct answer)

Question 4

• What is the molecular formula for an alkane with 13 carbon atoms?

  • Formula: C_nH_(2n+2)

  • Answer: a. C13H28 (correct answer)

Question 5

• Name the structure provided (from Chapter 16).

  • Example answers include:

    • a. butane

    • b. isoheptane

    • c. isopentane

    • d. hexane

    • e. neopentane

Question 6

• Which is the condensed structural formula for nonane?

  • a. CH3CH2CH2CH2CH2CH2CH2CH2CH3 (correct answer)

Question 7

• What is the condensed formula of the pictured structure?

  • b. CH3CH2CH(CH3)CH2CH3 (correct answer)

Question 8

• Identify the condensed structural formula (from the hints).

Question 9

• Name the pictured structure (parent chain is Heptane)?

Question 10

• What is the IUPAC name of the compound with CH3CH(CH3)CH2Br?

Question 12

• What are compounds with atoms joined in a ring?

  • b. Cycloalkanes (correct answer)

Question 13

• Identify the simplest cycloalkane.

  • d. Cyclopropane (correct answer)

Question 14

• What is the molecular formula for cyclohexane?

  • d. C6H12 (correct answer)

Naming Alkanes and Cycloalkanes

• Importance of skeletal structures in identifying branches and correct naming conventions.

• Review IUPAC naming conventions based on the structure provided in Chapter 16 materials.