What is the difference adsorption and absorption
What is the difference adsorption and absorption
Adsorption means attached to outside of solid, and absorption means penetration inside of solid.
Why are many ionic precipitates washed with electrolyte solution instead of pure water?
Because increasing the electrolye concentration decrease the thickness of ionic atmosphere and allows particles to come closer together before electrostatic repulsion becomes significant.
Why would a reprecipate be employed in a gravimetric analysis?
During the first precipitate the concentration of unwanted species in solution is greater giving a relatively high concentration of impurites in precipitate. In the reprecipitate, level of sol. Impurites is less giving a purer precipitate.
Why is it less desirable to wash AGCl precipitate with aqueous NaNO3 than with HNO3 sol?
HNO3 evaporates during drying. NaNO3 is nonvolatile and will lead to high mass for precipitate.
How is an inclussion differ from occlusion?
Inclusions are impurity ions that randomly occupy sites inthe crystal lattice normally occupied by ions that belong in the crystal. Occlussions are pockets of impuritt that are literally has not been exceeded
What measures can be taken to decrease the relative supersaturation during a precipitation?
Increasing temp mixing well during addition of precipitant and using dilute reagents. Homogenous precipitation is also an dxcellent way to control relative supersaturation
Why is high relative supersaturation undesirable in a gravimetric precipitate?
Leads to formation of colloidal product with large amount of impurities
Four desirable properties of a gravimetrix precipitate
Pure, insoluble, easily filterable, and a known composition
