SOLVENT CHOICE Flashcards
(9 cards)
What is the general principle of solvents?
Like dissolves like - e.g non polar dissolves non polar
Why do polar solvents dissolve polar substances?
Due to permanent dipole-dipole interactions or formation of hydrogen bonds between solute and solvent
Why do larger covalent molecules have a lower solubility?
Their solubility decreases as the polar part of the molecule is a smaller part of the overall structure
Do polar substances dissolve well in non polar solvents - why?
No as their dipole-dipole attractions are unable to interact
Why don’t giant covalent substances dissolve in any solvents?
The energy needed to overcome strong covalent bonds in lattice structures are too great
What do ionic compounds dissolve in?
Polar solvents
What does solubility of ionic compounds depend on?
- breaking down ionic lattice (relative strength of electrostatic forces of attraction within ionic lattice and attraction between ions and polar molecule)
- greater ionic charge = less soluble compound
How do polar molecules break down ionic lattice?
- partially positive end of polar molecule surrounds the negative anion
- partially negative end of polar molecule surrounds positive cation
Why are haloalkanes partially soluble in water?
They cannot form hydrogen bonds as there’s no H-F, H-O or H-N bonds within molecule
