PHA 317 practical test UPDATED ACTUAL Questions and CORRECT Answers
a system in which saturated insoluble solids are heterogeneously dispersed in a
What is a suspension?
liquid
is a a suspension made up of 2 immiscible liquids , where one liquid is dispersed as
fine droplets and the other is the continuous liquid phase
What is an emulsion?
- a dispersed phase
- a continuous phase
what is a solution? A homogeneous mixture of two or more substances
, - surfactants or wettings agents
what do we use to stabilise suspensions? -particles have greater density than their surrounding phase
-they sit on the interphase between the solid and liquid to reduce interfacial tension
V= [2ga2 (P1-P2)] \ [9n]
V=sedimentation rate
g= gravitational acceleration
what is stokes law equation?
a= radius of solid particles
P1= density of dispersed phase
P2= density of continuous phase
n= viscosity of continuous phase
what does stokes law mean the sedimentation of particles in a suspension
what happens when you reduce particle the reduction of particle size will reduce the sedimentation rate and so therefore will
size in suspension? enhance the suspension stability
what is the dispersed phase? the insoluble particles in the continuous phase
what is the continuous phase? Medium in which particles are dispersed.
what is the sedimentation ratio equation? Volume of sediment/ Total volume of suspension
what happens if the particle size is reduced the fine particle can sediment slowly and tightly pack together without larger spaces
too much? this can cause caking and results in impossible redispersion
- keep particle size higher to avoid caking
how to prevent too much particle reductio
-addition of flocculating agents
they allow particles to aggregate together by forming loose clump with larger
what is the role of flocculating agents in
spaces instead of tightly packed spaces.
suspension?
this prevents caking and allows for easy redispersion
they are oppositely charge to the dispersed phase particles so act as good
why are electrolytes used in suspensions? flocculating agents
-produces good suspensions that's settles quickly and redisperses easily
what is the result of too much electrolytes will cover the charged particles to make them repulsive to each other which causes
added? slow sedimentation and therefore caking occurs
particles aren't close together to begin with, over time break energy barrier and fuse
What is a deflocculated suspension?
to form cakes via slow sedimentation and too much electrolytes added
what is the dispersed phase in suspensions bismuth subnitrate
practical?
what is the continuos phase in suspensions water
practical?
bentonite
what is the suspensions stabiliser?
- will be the wetting agent to increase viscosity
KH2P04
what is the electrolyte in suspension's?
-monopotassium phosphate
Trisodium citrate
what is the flocculating agent in -will prevent caking and allows easy redispersion
suspensions? -increase in repulsion and particles aggregation with larger gaps so they can be
easily redispersed
what is the role of glycerin? it attracts water as a wetting agent to prevent suspension from drying out
a system in which saturated insoluble solids are heterogeneously dispersed in a
What is a suspension?
liquid
is a a suspension made up of 2 immiscible liquids , where one liquid is dispersed as
fine droplets and the other is the continuous liquid phase
What is an emulsion?
- a dispersed phase
- a continuous phase
what is a solution? A homogeneous mixture of two or more substances
, - surfactants or wettings agents
what do we use to stabilise suspensions? -particles have greater density than their surrounding phase
-they sit on the interphase between the solid and liquid to reduce interfacial tension
V= [2ga2 (P1-P2)] \ [9n]
V=sedimentation rate
g= gravitational acceleration
what is stokes law equation?
a= radius of solid particles
P1= density of dispersed phase
P2= density of continuous phase
n= viscosity of continuous phase
what does stokes law mean the sedimentation of particles in a suspension
what happens when you reduce particle the reduction of particle size will reduce the sedimentation rate and so therefore will
size in suspension? enhance the suspension stability
what is the dispersed phase? the insoluble particles in the continuous phase
what is the continuous phase? Medium in which particles are dispersed.
what is the sedimentation ratio equation? Volume of sediment/ Total volume of suspension
what happens if the particle size is reduced the fine particle can sediment slowly and tightly pack together without larger spaces
too much? this can cause caking and results in impossible redispersion
- keep particle size higher to avoid caking
how to prevent too much particle reductio
-addition of flocculating agents
they allow particles to aggregate together by forming loose clump with larger
what is the role of flocculating agents in
spaces instead of tightly packed spaces.
suspension?
this prevents caking and allows for easy redispersion
they are oppositely charge to the dispersed phase particles so act as good
why are electrolytes used in suspensions? flocculating agents
-produces good suspensions that's settles quickly and redisperses easily
what is the result of too much electrolytes will cover the charged particles to make them repulsive to each other which causes
added? slow sedimentation and therefore caking occurs
particles aren't close together to begin with, over time break energy barrier and fuse
What is a deflocculated suspension?
to form cakes via slow sedimentation and too much electrolytes added
what is the dispersed phase in suspensions bismuth subnitrate
practical?
what is the continuos phase in suspensions water
practical?
bentonite
what is the suspensions stabiliser?
- will be the wetting agent to increase viscosity
KH2P04
what is the electrolyte in suspension's?
-monopotassium phosphate
Trisodium citrate
what is the flocculating agent in -will prevent caking and allows easy redispersion
suspensions? -increase in repulsion and particles aggregation with larger gaps so they can be
easily redispersed
what is the role of glycerin? it attracts water as a wetting agent to prevent suspension from drying out
