Kafli 3 - Æfingar

Æfingar

3.1 Virknihópar

Use Table 3.1 to identify the functional groups in each of the following molecules:

(a)

The chemical structure of methionine which is an amino acid.

(b)

The chemical structure of ibuprofen which is a pain reliever.

(c)

The chemical structure of capsaicin which is the pungent substance in chili peppers.

(a) Sulfide, carboxylic acid, amine

(b) Aromatic ring, carboxylic acid

(c) Ether, alcohol, aromatic ring, amide, CC bond

Propose structures for simple molecules that contain the following functional groups:

(a) Alcohol

(b) Aromatic ring

(c) Carboxylic acid

(d) Amine

(e) Both ketone and amine

(f) Two double bonds

(a) The chemical structure of methanol that has an alcohol functional group.

(b) The chemical structure of toluene that has an aromatic ring functional group.

(c) The chemical structure of acetic acid that has a carboxylic acid functional group.

(d) The chemical structure of methylamine that has an amine functional group.

(e) The chemical structure of methyl acetamide that has a carbonyl and an amino functional group.

(f) The chemical structure of 1,3-butadiene that has two double bonds functional group.

Identify the functional groups in the following model of arecoline, a veterinary drug used to control worms in animals. Convert the drawing into a line-bond structure and a molecular formula (red = O, blue = N, black = C, gray = H).

The ball and stick model of arecoline where grey, black, blue and red spheres represent hydrogen, carbon, nitrogen, and oxygen, respectively.

The chemical structure of arecoline that has two functional groups, amine and a double bond.

3.2 Alkanar og hverfur alkana

Draw structures of the five isomers of C₆H₁₄.

The molecular structures of five isomers of hexane.

Propose structures that meet the following descriptions:

(a) Two isomeric esters with the formula C₅H₁₀O_2:

(b) Two isomeric nitriles with the formula C₄H₇N

(c) Two isomeric disulfides with the formula C₄H₁₀S₂

(a) The molecular structures of three isomeric esters of ethyl propionate.

(b) The molecular structures of two isomeric nitriles of butyronitrile are represented.

(c) The molecular structures of three isomeric disulfides of diethyl disulfide.

How many isomers are there with the following descriptions?

(a) Alcohols with the formula C₃H₈O

(b) Bromoalkanes with the formula C₄H₉Br

(c) Thioesters with the formula C₄H₈OS

(a) Two

(b) Four

(c) Four

3.3 Alkílhópar

Draw the eight 5-carbon alkyl groups (pentyl isomers).

The molecular structures of eight pentyl isomers are represented.

Identify the carbon atoms in the following molecules as primary, secondary, tertiary, or quaternary:

(a)

The molecular structure of 2-methylpentane

(b)

The molecular structure of 3-ethyl-2-methylpentane is represented

(c)

The molecular structure of 2,2,4-trimethylpentane is represented

(a) The molecular structure of 2-methylpentane featurings three primary carbons, two secondary carbons, and one tertiary carbon.

(b) The molecular structure of 3-ethyl-2-methylpentane is represented featuring four primary carbons, two secondary carbons, and two tertiary carbons.

(c) The molecular structure of 2,2,4-trimethylpentane featuring five primary carbons, one secondary carbon, one tertiary carbon, and one quaternary carbon.

Identify the hydrogen atoms on the compounds shown in Problem 3-8 as primary, secondary, or tertiary.

Primary carbons have primary hydrogens, secondary carbons have secondary hydrogens, and tertiary carbons have tertiary hydrogens.

Draw structures of alkanes that meet the following descriptions:

(a) An alkane with two tertiary carbons

(b) An alkane that contains an isopropyl group

(c) An alkane that has one quaternary and one secondary carbon

(a) The molecular structure of 2,3-dimethylbutane with two tertiary carbons is represented.

(b) The molecular structure of 3-isopropylpentane is represented

(c) The molecular structure of 2,2-dimethylbutane that has one quaternary and one secondary carbon is presented.

3.4 Nafngiftir alkana

Give IUPAC names for the following compounds:

(a)

The three isomers of C 5 H 12 are presented named pentane, 2-methylbutane, and 2,2-dimethylpropane.

(b)

The molecular structure of 2,3-dimethylpentane featuring a five-carbon chain.

(c)

The molecular structure of 2,4-dimethylpentane featuring a five-carbon chain.

(d)

The molecular structure of 2,2,5-trimethylhexane featuring a six-carbon chain.

(a) Pentane, 2-methylbutane, 2,2-dimethylpropane

(b) 2,3-Dimethylpentane

(c) 2,4-Dimethylpentane

(d) 2,2,5-Trimethylhexane

Draw structures corresponding to the following IUPAC names:

(a) 3,4-Dimethylnonane

(b) 3-Ethyl-4,4-dimethylheptane

(c) 2,2-Dimethyl-4-propyloctane

(d) 2,2,4-Trimethylpentane

(a) The molecular structure of 3,4-dimethylnonane is represented featuring a nine-carbon chain.

(b) The molecular structure of 3-ethyl-4,4-dimethylheptane featuring a seven carbon chain.

(c) The molecular structure of 2,2-dimethyl-4-propyloctane featuring an eight-carbon chain.

(d) The molecular structure of 2,2,4-trimethylpentane featuring a five-carbon chain.

Name the eight 5-carbon alkyl groups you drew in Problem 3-7.

Pentyl, 1-methylbutyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl

Give the IUPAC name for the following hydrocarbon, and convert the drawing into a skeletal structure.

A ball and stick model of a hydrocarbon that includes a central methine group, which is bonded to a methyl group at the top.

The skeletal structure of 3,3,4,5-tetramethylheptane featuring a seven-carbon chain.

3.7 Afbrigði annarra alkana

Make a graph of potential energy versus angle of bond rotation for propane, and assign values to the energy maxima.

A line graph of potential energy versus angle of rotation, for propane.

Sight along the C2–C1 bond of 2-methylpropane (isobutane).

(a) Draw a Newman projection of the most stable conformation.

(b) Draw a Newman projection of the least stable conformation.

(c) Make a graph of energy versus angle of rotation around the C2–C1 bond.

(d) Assign relative values to the maxima and minima in your graph, given that an H ⟷ H eclipsing interaction costs 4.0 kJ/mol and an H ⟷ CH₃ eclipsing interaction costs 6.0 kJ/mol.

(a) A Newman projection of the most stable conformation is represented.

(b) A Newman projection of the least stable conformation is represented. It contains energy of 4 and 6 kilojoules per mol.

(c) A line graph of energy versus angle of rotation, around the C2 – C1 bond.

(d) A line graph of energy versus angle of rotation, around the C2 – C1 bond.

Sight along the C2–C3 bond of 2,3-dimethylbutane, and draw a Newman projection of the most stable conformation.

A Newman projection of 2,3-dimethylbutane, the most stable conformation is represented.

Draw a Newman projection along the C2–C3 bond of the following conformation of 2,3-dimethylbutane, and calculate a total strain energy:

A ball and stick model of 2,3-dimethylbutane featuring a four-carbon chain.

A Newman projection of 2,3-dimethylbutane with a total energy of 11.4 kilojoules per mole is represented.