CHAPTERS 6.1 & 6.2

Question 1

what happens when a solid, liquid or gas is dissolved in a liquid?

Answer 1

• solute particles attract to solvent particles
• solute particles separate from each other
• solvent particles not attached to solute particles will still be attracted to other solvent particles
• the forces involved are intermolecular

Question 2

what does ‘like dissolves like’ mean?

Answer 2

whatever intermolecular bonds in the solvent are broken, they need to be repaired by similar bond formation between the solute and solvent. polar solvents dissolve polar solutes and non-polar solvents dissolve non-polar solutes

Question 3

what forces are involved in dissolving?

Answer 3

hydrogen bonds and dispersion forces

Question 4

what does dissociation mean?

Answer 4

when ionic compounds dissolve in polar solvents. not all ionic compounds are soluble in water

Question 5

why don’t insoluble ionic compounds dissolve in water?

Answer 5

because the forces of attraction between the ions in the lattice (ionic bonds) are much stronger than the forces of attraction between water molecules and the ions in the lattice (ion-dipole attraction)

Question 6

what is chromatography?

Answer 6

the analytical technique that is based on the differences in the solubility of compounds

Question 7

what are the two phases present in chromatography?

Answer 7

• stationary phase
• mobile (moving) phase

Question 8

how do you calculate the retardation factor (Rf)?

Answer 8

Rf = distance moved by solute / distance moved by solvent