Question

Classify the substances according to the strongest solute-solvent interaction that will occur between the given substances and water during dissolution.
1.ion-ion forces2.dipole dipole forces3.ion dipole forces4.london dispersion forcesA. HFB. CH3OHC. CaCl2D. FeBr3

Answer 1

Answer:

A.  Dipole-dipole forces; B. dipole-dipole forces;

C. ion-dipole forces; D. ion-dipole forces

Explanation:

A. HF

HF is a weak acid but a highly polar molecule. The strongest intermolecular force with water is an especially strong dipole-dipole force (hydrogen bonding) of the type

H-F· · ·H-OH and H₂O· · ·H-F

B. CH₃OH

CH₃OH has a highly polar O-H bond. The strongest intermolecular force with water is the especially strong dipole-dipole force (hydrogen bonding):

CH₃(H)O· · ·H-OH and CH₃O-H· · ·OH₂

C. CaCl₂

CaCl₂(s) ⟶Ca²⁺(aq) + 2Cl⁻(aq)

CaCl₂ separates into hydrated ions in solution. The strongest intermolecular force with water is ion-dipole attraction.

Ca²⁺· · ·OH₂ and Cl⁻· · ·H-OH

D. FeBr₃

FeBr₃(s) ⟶Fe³⁺(aq) + 3Br⁻(aq)

FeBr₃ separates into hydrated ions in solution. The strongest intermolecular force with water is ion-dipole attraction.

Fe³⁺· · ·OH₂ and Br⁻· · ·H-OH