This preview shows page 1. Sign up to view the full content.
Unformatted text preview: Chemistry 2311 Homework Problems‐ Chapter 2 Section 1: Circle the number which corresponds to the answer to each of the following questions. There is only one correct answer for each question. (a) Which of the following bonds has the greatest bond dissociation energy? (1) C‐C (2) C‐Cl (3) C‐O (4) C‐F (b) Which of the following bond has the greatest bond moment? (1) C‐C (2) C‐Br (3) C‐O (4) C‐N (c) Which of the following molecules will have the greatest dipole moment? F3C
(1) CF3 C C H
H H F3C
(2) C H C CF3 (3) F3C
F3 C C C
CF3 CF3 (4) C F3 C C CF3 (d) What are the functional groups to which the arrows are pointing? O O C OCH3 NH2 CH2 OH C O (e) Which of the following structures is a tertiary amine? CH3
(1) CH3 CH3
(2) H3C N H3C N H H
(3) (4) CH3 H H3C C CH3 NH2 H3C N (f) Which of the following molecules has the highest boiling point? H3C
(1) CH3 C C CH2OH H3C
(2) CH3 C C CO2H H H H3C
(3) CH3 C C CO2CH3
(4) H3C C H C CH3 COCH3 H (g) Which of the following molecules has the greatest solubility in water? O H OH (1) (2) H OH O (3) (4) H OH H OH Section II: Indicate True (T) or False (F) for each of the following statements: (a) Benzene is an equilibrium mixture of two constitutional isomers. (b) Electronegativity is the ability of an element to attract electron that it is sharing in a covalent bond. (c) A dipole moment is a vector; it has magnitude and direction. (d) The melting point of a substance is the temperature at which an equilibrium exists between the well‐ordered crystalline state and the more random liquid state. (e) Dipole‐dipole forces are stronger than ion‐ion forces. (f) A hydrogen bond is formed by hydrogen acting a bridge between two highly electronegative elements. (g) Polarizability is a measure of ease of response of electrons in an atom or molecule to a change in electric field. (h) The boiling point of a liquid is the temperature at which the vapor pressure of the liquid equals the pressure of the atmosphere above it. (i) Methanol (CH3OH) is more soluble in water than 1‐pentanol (CH3CH2CH2CH2CH2OH) because the C5H11 unit attached to the OH in 1‐pentanol is more hydrophilic than the CH3 unit in methanol. (j) The frequency of a given stretching vibration in an IR spectrum can be related to (1) the mass of the bonded atoms, and (2) the relative stiffness of the bond. (k) In order for a vibration to occur with the adsorption of IR energy, the dipole moment of the molecule must change as the vibration occurs. Section III: Identify the functional groups present in each of the following IR spectra. Draw the functional group adjacent to the particular absorption band. ...
View Full Document