A colloidal solution of gold nanoparticles is prepared by reduction of . Which of the following methods is MOST EFFECTIVE for purifying this solution from excess reactants and small ionic byproducts?
Filtration
Centrifugation
Dialysis
Evaporation
Related Questions
A binary liquid mixture of components A and B exhibits an azeotrope at a specific composition. Which of the following statements is ALWAYS true about this azeotropic mixture?
The composition of the vapor phase is identical to the composition of the liquid phase.
The boiling point of the azeotrope is the average of the boiling points of pure A and B.
The azeotrope can be separated into pure A and B by fractional distillation.
The azeotrope always shows a positive deviation from Raoult's Law.
Crystallization is a purification technique based on the principle of:
Difference in solubility of the compound and impurities at different temperatures
Difference in melting points of the compound and impurities
Difference in boiling points of the compound and impurities
Difference in densities of the compound and impurities
In chromatography, the component that travels the furthest on the chromatogram is the one that is:
Most soluble in the mobile phase and least adsorbed to the stationary phase
Least soluble in the mobile phase and most adsorbed to the stationary phase
Equally soluble in both phases
Insoluble in both phases
Which of the following methods is NOT typically used for concentrating a dilute ore?
Froth flotation
Magnetic separation
Gravity separation
Distillation
A binary solution of liquids A and B shows positive deviation from Raoult's law. Which of the following statements is TRUE?
The intermolecular forces between A and B are weaker than those between A-A and B-B.
The intermolecular forces between A and B are stronger than those between A-A and B-B.
The solution exhibits a negative deviation from Raoult's law.
The total vapor pressure of the solution is less than the sum of the vapor pressures of the pure components.
Reactants react in the equal number of …….. to give products.
Mole
Weights
Equivalent
All of these
The speed of sound in air is dependent on temperature. Which of the following correctly describes this relationship?
Speed of sound decreases with increasing temperature
Speed of sound increases with increasing temperature
Speed of sound is independent of temperature
Speed of sound initially increases then decreases with increasing temperature
In the leaching of alumina from bauxite, the concentration of the ore is achieved by:
Selective dissolution of alumina
Froth flotation
Magnetic separation
Electrolysis
Which of the following physical properties of a metal is significantly affected by changes in temperature?
Density
Mass
Volume
Resistivity
Which concentration term is independent of temperature?
Molarity
Molality
Normality
Formality
