1. What does the solid-liquid separation operation don’t involve?
a) Gravity sedimentation
b) Magnetic separation
c) Filtration
d) Centrifugation
Explanation: The solid-liquid separations always involve gravity sedimentation, filtration and centrifugation. Magnetic separation is not involved.
2. What process happens in leaching?
a) A solvent separates a mixture
b) Two solvents separate a mixture
c) A solvent selectively dissolves one of the component
d) The mixture is heated so that one solid sublimes and is separated.
Explanation: Leaching is process where a solvent selectively dissolves some of the solid components from a multi component solid mixture
3. What happens in an ideal leaching stage of a mixture of A and B?
a) The solvent dissolves Some B and some A
b) The solvent dissolves none of A and all B
c) The solvent dissolves all of A and B, which makes separation easier
d) The solvent does not dissolves any of A and B
Explanation: In an ideal leaching stage the solvent dissolves none of A and all B which will make the separation most easy.
4. What increases the solute concentration?
a) Increasing viscosity of the liquid phases
b) Decreasing viscosity of liquid phases
c) Increasing temperature of liquid phases
d) Decreasing temperature of liquid phases
Explanation: If the viscosity of the liquid phases is increased, the is an increase in the concentration of solute.
5. What is a eutectic point?
a) A temperature at which the mixture boils
b) The temperature at which the mixture gets out of equilibrium
c) The temperature at which the components have same molar flow rates
d) The temperature at which the mixture freezes
Explanation: Eutectic point is a temperature at which a mixture freezes.
6. What is needed because of crystals occluding liquid?
a) Centrifugation
b) Distillation
c) Drying step
d) Decantation
Explanation: A drying step is necessary because a crystal occludes solid
7. What is correct about the hydrate?
a) A high hydrate exists at low temperatures and low hydrste is unlikely to exist
b) A low hydrate exists at high temperature and a low hydrate exists at high temperature
c) A high hydrate exists at high temperature and a low hydrate exists at high temperature.
d) A hydrate does not exist at high temperature
Explanation: Due to more water molecules present , the high hydrate will be unstable at high temperatures.
8. What happens during adsorption process of solid-liquid separation?
a) The adsorbent adsorbs liquid in the interior and solid in the exterior
b) The adsorbent adsorbs liquid In the interior and the exterior
c) The adsorbent adsorbs solid in the interior and liquid in the exterior
d) The adsorbent adsorbs solid in the interior and the exterior
Explanation: In adsorption, a solid agent adsorbs liquid phasein the interior and the exterior.
9. Which laboratory methods give a rough prediction about adsorption-equilibrium curves?
a) Isobaric calculation
b) Flow charts
c) Adsorption isotherms
d) Absorption isotherms
Explanation: Adsorption isotherms provide a rough idea about the adsorption-equilibrium.
10. The freundlich equation is of the form:
a) qi = Aci (1/n)
b) cBQ=q*BS
c) qi = Aci(n)
d) qi = Aci
Explanation: The freundlich isotherm is of the form qi = Aci (1/n) which can be
converted to y=mx + c by taking logarithms on both sides.