# PHA 327 - Exam 2 - Suspensions 3

 What is sedimentation volume (F)? The ratio of the final volume of the sedimen (Vu) t to the original volume of the suspension (Vo)F = Vu/Vo What value of F (sedimentation Volume) indicates that the suspension if in flocculated equilibrium and show no clear supernant on standing. 1 What is the equation for Sedimentation Height? Sedimenation Height = Hultimate/Horigional What are the two interactive forces between particles in a suspension? London forces (attractive)Zeta potential (repulsive) What type of interactive force is the Zeta potential? Repulsive What force in a suspension provides repulsion between particles? Zeta potential What type of interactive forces are London forces? Attractive What force in a suspension provides attractive interactions between particles? London forces What are London forces? Forces by which non-polar molecules induce polarity in each other What is the term for the situation where non-polar particles induce polarity in one another? London forces Is the Zeta potential or London forces stronger? Zeta potential When particles are dispersed by the Zeta potential, what is the term used to describe them? Deflocculated What two types of interactions between particles exist in a suspension? Flocculation or CakingDeflocculation Wht are loose aggregates of particles in a suspension called? Flocs What is a floc? A loose aggregate of particles in a suspension When a suspension is deflocculated how do repulsive and attractive forces compare? Repulsion>Attraction When a suspension is flocculated how do repulsive and attractive forces compare? Repulsion What is a flocculating agent? An opposing ion to the adsorbate on the particle that increases attractive forces and causes flocculation When you continue adding the flocculating agents until its charge predominates, what happens? The repulsive forces will again predominate, resulting in deflocculation What are the four characteristics of a flocculated suspension? Distinct boundary between supernant and sedimentSupernant is clearFluffy conglomerates (weakly bound)Settles rapidly but no cake formation What are the five characteristics of a deflocculated suspension? Repulsion is high energyNo distinct boundary between supernant and sedimentCloudy supernantParticles settle slowlyCake formation over time which is very difficult to resuspend Does a deflocculated or flocculated suspension form a cake? Deflocculated Does a deflocculated of flocculated suspension have a cloudy supernant? Deflocculated What type of flocculated system is most preferred due to its stability advantage? Controlled flocculated suspension Why is a Controlled flocculated suspension preferred? It is more stable What are commonly used reducers of Zeta potential? ElectrolytesAlcohols What is the most commonly used reducer of Zeta potential? Electrolytes What do surfactants do in a suspension? Forms an adsorbed monolayer on the particle surface What substances form an adsorbed monolayer on the outside of the particle surface in a suspension? Surfactants What type of action do polymers have on suspensions? Protective colloid action Authorkyleannkelsey ID214989 Card SetPHA 327 - Exam 2 - Suspensions 3 DescriptionPHA 327 - Exam 2 - Suspensions 3 Updated2013-04-22T04:23:04Z Show Answers