Kaplan Chemistry: Chapter 9 Solutions Flashcards
what is solvation
electrostatic interaction between solute and solvent molecules
when electrostatic interations are stronger than the original ones in the reactants, the solvation energy is ____
exothermic.
when the new interactions are weaker than the original interactions int he reactiants, the solvation is ___
nedothermic.
trend of entropy upon dissolution
at contant temp and pressure, entropy always increases upon dissolution.
what is the solubility of a spontaneous dissolution reaction
if G is negative, than the reaction is spontaneous and the solute is soluble.
percent composition by mass formula
(mass solute/mass of solution)x 100
molality
moles of solute/kg of solvent.
what entity is used to calculate boiling point elevation and freezing point depression?
a. molarity
b. molality
c. normality
d. molefraction
molALITY.
dilution equation
c1v1 = c2v2
how can solubility of gases be increased?
solubility of gases can be increased by DECREASING the temp and INCREASING the partial pressure of the gas above the solvent (henry’s law)
if an anion is insoluble in neutral water, but, dissolves in an acidic solution, the anion is most likely ___
basic.
___ pressures favor the dissolution of gas solutes
High pressure
in solution chemistry, Q is the “equilibrium “ constant. What is it also known as?
ion product constant
high vapour pressure = ___ evaporates
easily evaporates
t/f colligatie properties are dependent on the identity of the chemical
FALSE. they are only dependent on the concentration of the dissolved particles.
name the colligative properties (4)
1) vapour pressure
2) boiling point
3) freezing point depression
4) osmotic pressure.
raoults law
as solute is added to the solvent, the vapour pressure DECREASES. This is because it is harder for solvent particles to interact with one another. therefore, solute moelcules can BLOCK evaporation of the solvent by decreasing their vapour pressure.
boiling point elevation is when vapour pressure =
ambient pressure.
as solute is added to the solvent, the boiling point __
increases. a BP is the temp where CP = ambient pressure. if VP of a solution is lower than that of the pure solvent, then more energy will be required before its vapor pressure = ambient pressure.
equation for boiling point elevation
Tb = iKbm m= molality
which colligative property of a substance will give the best estimate of its relative vapour pressure?
boiling point elevation.
as solute is added to the solvent, the freezing point ____
decreases. this is known as freezing point depression .this occurs because solute particles interferes with the formation of lattice structures.
T/F: osmotic pressure also uses molality.
false. only freezing point depression and boiling point elevation uses molality (mol solute /kg of solvent). osmotic pressure = iMRT. M is MOLARITY (concentration).
the higher the molarity of the solute, the ___ osmotic pressure
MORE osmotic pressure
the higher the molarity of the solvent, the ___ osmotic pressure
LESS osmotic pressure. the solute is diluted in a lot of solvent.
a faraday is equal to one mole of:
electric charge.
ex/ because an aluminum ion gains 3 electrons 0.1 faraday of charge will reduce 0.1/3 moles of aluminum, or 0.033 mols of aluminum
