electical properties

Question 1

what does electrical properties of colloids depend on

Answer 1

surface charge of a particle; most particles in contact with a polar medium have surface charge

Question 2

what does surface electrical charge acquire from

Answer 2

ionisation, ion adsorption, ion dissolution.

Question 3

what is ion adsorption

Answer 3

unequal adsorption of oppositely charged ions +ve and -ve

Question 4

what particles more prone ion adsorption

Answer 4

small less hydrated & more polarizing anions are more prone to be adsorbed onto particles (-ve often) aq medium.

ionic sufectants are strongyly adsorbed too and have massive influence on surface charge either +/-ve depending upon the ionic character.

charged particles tend to adsorb counterions. adsorption may lead to charge reversal on the particle.

Question 5

what is ion dissolution

Answer 5

formation of ions through unequal dissolution of the charged ions

Question 6

what is electron double layer

Answer 6

charged portic
counterions attracted to surface; approach inhibited by hydration sphere
stem layer; e potential < surface potential
beyond stem plane more counterions are attracted; electrial neutrality