Chem 31.1 Expt 1 AtoQ

Answers to Questions

1. For solutes that are dissolved because of intermolecular attractions with the solvent, state the intermolecular attractions involved.

Intermolecular Attractions
F
There are dipole-dipole attractions and hydrogen bonding between polar acetone and polar water.
J
There are dipole-dipole attractions and hydrogen bonding between ethanol and water. There are also dipole-dipole attractions between ethanol and diethyl ether.
L
There are hydrogen bonding, dipole-induced dipole forces, and dipole-dipole forces between sucrose and water.

2. For solutes that are dissolved because of reaction with the solvent, write the balanced equation involved.

Balanced Equation
A

C6H5OH + NaOH  C6H5ONa + H2O

D

C6H5CHO + H2SO4  m-benzaldehyde sulfonic acid

E
C6H5CH2OH + H2SO4  C6H5CH2OH2+ + HSO4-

G

C6H5COOH + NaOH  C6H5COONa + H2O

C6H5COOH + NaHCO3  C6H5COONa + CO2 + H2O
H

C6H5NH2 + HCl → C6H5N+H3Cl-

3. On the basis of solubility behaviour, determine the best solvent to differentiate the following pairs of compounds.
a. CH3COOH (acetic acid) and CH3(CH2)5COOH
The best solvent to use to differentiate acetic acid from heptanoic acid would be sodium bicarbonate (NaHCO3) as the stronger the acid, the more soluble it is in sodium bicarbonate.
b. CH3CH2OCH2CH3 and CH3CH2OH
The best solvent to use to differentiate diethyl ether from ethanol is water. Diethyl ether is only slightly soluble in water unlike ethanol which is completely soluble.
c. toluene and benzaldehyde
The best solvent to use to differentiate toluene from benzaldehyde is concentrated sulfuric acid (H2SO4) since benzaldehyde is soluble in sulfuric acid unlike toluene.
d. tert-butyl chloride and tert-butanol
The best solvent to use to differentiate tert-butyl chloride and tert-butanol is water since tert-butanol is very soluble in water while tert-butyl chloride is not.

References:
Jain, M. (Ed.). (2008, June). Aromatic Conversions. Competition Science Vision, 474.

McMurry, J. (2011). Alcohols, Phenols, Ethers and Their Sulfur Analogs. Fundamentals of Organic Chemistry, 7th Edition (pp. 256-283). Belmont, CA: Brooks/Cole.

Solomons, G., Fryhle, C., & Snyder, S. (2014). Organic Chemistry, 11th Edition. USA: John Wiley & Sons, Inc.

Data:
Test Compound
Soluble in
Solubility Class
Compound
A
5% NaOH
A1
Phenol
B
None
I
Tert-butyl chloride
C
None
I
Toluene
D
Conc. H2SO4
N
Benzaldehyde
E
Conc. H2SO4
N
Benzyl alcohol
F
Water and diethyl ether
S1
Acetone
G
5% NaOH and 5% NaHCO3
A2
Benzoic acid
H
5% HCl
B
Aniline
I
None
I
Hexane
J
Water
M
Sucrose
K
None
S1
Benzamide
L
Water and diethyl ether
S2
Ethanol

References: Jain, M. (Ed.). (2008, June). Aromatic Conversions. Competition Science Vision, 474. McMurry, J Solomons, G., Fryhle, C., & Snyder, S. (2014). Organic Chemistry, 11th Edition. USA: John Wiley & Sons, Inc.