Chemistry Review Flashcards
What are colligative properties?
physical properties of solutions that are dependent on the concentration of dissolved particles but not on the chemical identity of the dissolved particles
What are examples of colligative properties?
vapor pressure depression, boiling point elevation, freezing point depression, and osmotic pressure
Why is there a reduction of vapor pressure when a solute is added to a solvent?
the presence of solute molecules can block the evaporation of solvent molecules but not their condensation
Raoult’s Law
P(A) = X(A)P(A)’
where,
P(A) = vapor pressure of solvent A when solutes are present
X(A) = mole fraction of the solvent A in the solution
P(A)’ = vapor pressure of solvent A in its pure state
How does boiling point elevation go hand in hand with vapor pressure depression?
if the vapor pressure of a solution is lower than that of the pure solvent, then more energy will be required before its vapor pressure equals the ambient pressure
How do you determine boiling point elevation?
ΔT(b) = iK(b)m
where,
i = van’t Hoff factor
m - molality of a solution
What impact do solutes have on the freezing point of a solvent?
the presence of solute particles in a solution interferes with the formation of the lattice arrangement of solvent molecules associates with the solid-state
The formula for calculating the freezing point depression for a solution
ΔT(f) = iK(f)m
What is an Arrhenius acid?
it dissociates to form an excess of H+ in solution
What is an Arrhenius base?
it dissociates to form an excess of OH- in solution
What is a Bronsted-Lowry acid?
species that donates hydrogen ions (H+)
What is a Bronsted-Lowry base?
species that accepts hydrogen ions
What is a Lewis acid?
electron-pair acceptor
What is a Lewis base?
electron-pair donor
How is the pH of a solution expressed?
pH = -log[H+]
How is the pOH of a solution expressed?
pOH = -log[OH-]
How do you determine pH when the value is given n x 10^-m?
-log[n x 10^-m] = -n - log(10^-m) = m - log(n)
move a decimal spot for n (divide n by 10)
How do you calculate the unknown concentration of a titrand during a titration?
N(a)V(a) = N(b)V(b),
where Na and Nb are acid and base normalities
Bicarbonate buffer system
CO2(g) + H2O(l) –> H2CO3(aq) –> H+(aq) + HCO3- (aq)
What is the equation used to estimate the pH or pOH of a buffer solution
pH = pKa + log[A-]/[HA] pOH = pKb + log[B+]/[BOH]
What is an oxidizing agent?
causes another atom in a redox reaction to undergo oxidation and is itself reduced
What is a reducing agent?
causes the other atom to be reduced and is itself oxidized
