Question

14. What type of intermolecular force causes the dissolution of NaCl in water? A) hydrogen bonding B) dipole-dipole forces C) ion-dipole force D) dispersion forces E) none of the above

15) Choose the molecule or compound that exhibits dipole-dipole forces as its strongest intermolecular force. A) H2 B) SO2 C) NH3 D) CF4 E) BCl3

16) Place the following compounds in order of increasing strength of intermolecular forces. CH4 CH3CH2CH3 CH3CH3 A) CH3CH2CH3 < CH4 < CH3CH3 B) CH3CH2CH3 < CH3CH3 < CH4 C) CH3CH3 < CH4 < CH3CH2CH3 D) CH4 < CH3CH2CH3 < CH3CH3 E) CH4 < CH3CH3 < CH3CH2CH3

17) Identify the compound that does not have hydrogen bonding. A) (CH3)3N B) H2O C) CH3OH D) HF E) CH3NH2

18) Choose the pair of substances that are most likely to form a homogeneous solution. A) NaCl and Hg B) LiF and C6H14 C) C3H8 and C2H5OH D) Br2 and PF3 E) NH3 and CH3OH

19) In liquid propanol, CH3CH2CH2OH which intermolecular forces are present? A) Dispersion, hydrogen bonding and dipole-dipole forces are present. B) Only dipole-dipole and ion-dipole forces are present. C) Only dispersion and dipole-dipole forces are present. D) Only hydrogen bonding forces are present.

Answer 1

(14) (C) Ion - dipole forces.

NaCl (aq.) ----------------> Na⁺ (aq.) + Cl^- (aq.)

There exists an attraction between Na⁺ and partial negatively charged O of H₂O AND Cl^- and partial positively charged H of H₂O

(15) (b) SO2. as it is a bent molecule.

H2, CF4 and BCl3 have dispersion forces among their molecules and NH3 has H-bonding.

(16) (E) CH4 < CH3CH3 < CH3CH2CH3

Increase in molecular weight increases the attractive forces.

(17) (A) (CH3)3N. Because of no N-H or O-H or F-H bond.

(18) (E) NH3 and CH3OH. Because of their ability to form H-bond.

(19) (A) Due to O-H Hydrogen bond

due to C-O dipole - dipole forces

due to C-C and C-H dispersion forces