1. A functional group is a structural arrangement of atoms that, because
of their electronegativity and bonding type,
imparts particular characteristics to the molecule.
2. Yes, C=C and C=C bonds are more reactive than C—C bonds because the second and third bonds formed are weaker than the first single bond formed, and are thus more readily broken, making the multiple bonds more reactive.
3. A polar molecule would have a boiling point higher than that of a less polar molecule; polar molecules have stronger intermolecular attractions, requiring more energy (higher temperatures) to separate them.
3. (a) 4-i-propyl-2,5-octadiene
Some answers must be done as pictures and cannot be placed here, therefore go to the picture page by clicking here
There may be some double answers in this section.
1, 2, 3 on picture page
4. (a) propanone
5. In order of increasing boiling points: propane (b); 1-propanone (a); 1-propanol (c). This order is predicted because (a) contains a carbonyl group (with a polar double bond), making it more polar than (b), which gives 1-propanone a higher boiling point than propane. 1-propanol contains a hydroxyl group, which can hydrogen bond with other molecules, giving (c) a higher boiling point than (a) or (b).
7. In increasing order of solubility: butane (c), 2-butanone (a), 1-butanol (b). Butane is a nonpolar hydrocarbon and is less soluble in water than the ketone (a) and the alcohol (b). The ketone (a) has a polar carbonyl group, making it more soluble in water than (c), but it is less soluble than the alcohol (b), which has a hydroxyl group that allows it to hydrogen bond.
8. Generally, the term “oxidation” means a reaction in which a substance gains oxygen atoms or loses hydrogen atoms. Further definitions of oxidation also include reactions that do not involve oxygen or hydrogen atoms.
Page 57 Questions
3. a) propanal
b) carbon dioxide and water
4. (a) The ether ethoxypropane will evaporate at a lower temperature
because it is less polar than the pentanal which
contains a polar carbonyl group.
(b) The ether ethoxypropane has higher solubility in nonpolar solvents because it does not contain any carbonyl groups and is less polar than the pentanal.
(c) The pentanal can undergo an addition reaction with hydrogen at its carbonyl group, but the ether cannot.
6. Experimental Design
The tertiary alcohol does not undergo controlled oxidation to aldehydes or ketones; each alcohol is allowed to react with sodium dichromate and the alcohol that does not cause a colour change in the dichromate solution is the tertiary alcohol. (Primary alcohols are oxidized to aldehydes, and secondary alcohols are oxidized to ketones.)
1. Set up three separate test tubes containing each of the alcohols.
2. Add the sodium dichromate solution, in the presence of H2SO4.
Do not use open flames. Sulfuric acid is corrosive; avoid contact with skin or clothing. Wear eye protection and a lab apron.
7. Experimental Design
1-butene is hydrolyzed with water, in the presence of acid, to produce 2-butanol. 2-butanol is then made to undergo controlled oxidation (e.g., in KMnO4) to produce butanone.
1. Place 1-butene in a container and add sulfuric acid.
2. Add KMnO4(aq) to the mixture.
Do not use open flames. Sulfuric acid is corrosive; avoid contact with skin or clothing. Wear eye protection and a lab apron. Work in a well-ventilated area. Dispose of organic materials in designated containers for collection.
4. The gas (A) has the lowest boiling point and must be the alkane, the least polar molecule. The liquid (B) has the next highest boiling point and must be the alcohol, which has a hydroxyl group. The solid (C) has a higher melting point than the liquid, and must be the acid which, with its carboxyl group, is the most polar of the three compounds.
5. CH3CH2CH2OH + (O) --->
CH3CH2CHO + H2O
CH3CH2CHO + (O) ---> CH3CH2COOH
12. (a) ethyl propanoate (from propanoic acid and ethanol)
(b) methyl butanoate (from butanoic acid and methanol)
(c) butyl methanoate (from methanoic acid and 1-butanol)
(d) propyl ethanoate (from ethanoic acid and 1-propanol)
SECTION 1.7 QUESTIONS (Page 68)
1. (a) propyl propanoate
(b) 2-methylpentyl propanoate
(c) 2-bromopropanoic acid
(d) ethanoic acid
(e) carboxybenzene or phenylmethanoic acid (commonly called benzoic acid)
4. (a) propanoic acid and 1-pentanol
(b) 2-ethylpentanoic acid and propanol
(c) benzoic acid and methanol
5. Heat the ester with a concentrated NaOH solution. The reaction is complete when the insoluble ester changes to soluble products.
6. Esters are less soluble than acids or alcohols in water and can be separated by pouring the reaction mixture into cold water; the ester forms an insoluble layer on top of the water.
2. (a) diethylamine, N-ethylaminoethane; 2° amine
(b) trimethylamine, N,N-diethylaminoethane; 3° amine
(c) i-propylamine, 2-aminopropane; 1° amine
(d) n-hexylamine, 1-aminohexane; 1° amine
(e) 2-bromo-6-N-methylaminohexane; N-methyl-N-5-bromohexylamine; 2° amine; 2° amine
PRACTICE (Page 76)
4. (a) N-ethyl butanamide
(b) N-methyl propanamide
(c) N,N-dimethyl propanamide
(d) N-ethyl-N-methyl pentanamide
6. (a) amine; propylamine
(b) amine; ethylmethylamine
(c) amide; ethanamide
SECTION 1.8 QUESTIONS (Page 78)
1. see picture page
2. (a) alcohol, amine; the OH group in alcohols is more polar than the NH group in amines, making them less soluble in nonpolar solvents than are amines.
(b) primary amine, tertiary amine; tertiary amines do not contain the polar NH groups that are present in primary amines. The more polar primary amine is less soluble in nonpolar solvents than is the tertiary amine. However, if the nonpolar group on the primary amine is large, the increased attraction between nonpolar groups may make it more soluble in the nonpolar solvents.
(c) tertiary amine, hydrocarbon; bonds between N and C are more polar than bonds between H and C, and therefore, tertiary amines are slightly more polar than hydrocarbons, making them less soluble in nonpolar solvents. However, if the nonpolar groups on the tertiary amine are large, the increased attraction between nonpolar groups may make it more soluble in the nonpolar solvents.
(d) low molecular mass, high molecular mass; both are primary amines with the same number of NH bonds. The higher molecular mass amine has a larger nonpolar hydrocarbon component and is therefore more soluble in nonpolar solvents.
5. (a) propanamide
(c) N,N-diethyl propanamide
(f) 2-aminoethanoic acid