Flashcards in Factors affecting solubility and rate of dissolving Deck (15):
rate of dissolving
the speed at which the solute dissolves in a solvent
increasing the surface area of the solute by crushing it
increasing the kinetic energy= higher collision frequency which means it dissolves faster
increases the rate of dissolving by allowing unsaturated portions of the solution to come in contact with the solute.
Factors affecting ROD
SA, heat, agitation
factors affecting solubility
temperature, pressure, molecule size, polarity, ionic size and charge
For most solid solutes, solubility increases
with heat. Heating increases the spaces between the solvent
molecules to allow for more solutes to dissolve.
To increase the solubility of gases in liquids, the temperature
must be dropped. The drop in temperature decreases the
speed of motion of the gas molecules and therefore, prevents
the gas molecules from escaping the liquid.
Increasing pressure increases the solubility of gases in liquids, but since solids and liquids are not compressible, we cannot change the pressure in order to change solubility of solids and liquids. Pressure has a great effect on the solubility of a gas only.
solubility: molecule size
Smaller molecules are more soluble than the larger ones.
Polar solutes dissolve better in polar solvents. Non- polar solutes dissolve better in non-polar solvents ("like dissolves like").
factors affecting solubility of ionic compounds
ion size: smaller the ion, less distance between nuclei, stronger the bond= harder to dissolve. attraction between the electron clouds of both ions is stronger
ion charge: stronger bond= harder to dissolve ex +2 and -2 is stronger than +1, -1
molar concentration of ions
multiply by the subscripts
what compounds are always soluble?
all compounds of alkali metals, ammonium and nitrates are water soluble
liquid in liquid solubility and temperature
When two liquids at the same temperature mix to form a solution, there is usually little or no energy exchanged between the particles of the liquids. For tis reason, the solubility of one liquid in another liquid is not affected by temperature