Colligative Properties
What are the colligative properties?
- Vapor pressure
- boiling point elevation
- freezing point depression
- osmotic pressure
How do you know when you can use a small X approximation?
If the change is less than 5% of the reactant initial concentration
What is the difference between a Brønsted–Lowry Base and a Lewis base
Brønsted–Lowry base: Proton (H+) acceptor
Lewis Base: Electron donor
What is the difference between a galvanic and a voltaic cell?
There is no difference, they are the same thing!
Rank the 4 intermolecular forces from weakest to strongest
London dispersion forces -> dipole-dipole -> hydrogen bonding -> ion dipole
If an exothermic reaction is increased in temperature, which direction will the equilibrium shift
Equilibrium will shift towards the reactants (reverse)
What is it called when a species can act both as an acid or as a base
Amphoteric
True or false: An electrolytic cell makes electricity, it will therefore have a negative Ecell
false: while electrolytic cells do have a negative Ecell, they do not produce electricity (a galvanic cell does this). The negative Ecell represents the non-spontaneous nature of the cell, requiring energy be put into the cell for it to progress
When a solute dissolves in a solvent and yields multiple ions, it will effect the colligative properties of that substance. What is this effect called?
i = Van't Hoff Factor
True or false: If the Kc is greater than the Qc, the reaction is nonspontaneous and will not occur
False: a higher Kc than Qc would indicate the reaction has not yet reached equilibrium and will continue in the forward direction.
What is the relationship between ka and kb?
kw = ka kb
Ecell = Ecathode + Eanode
Is the Eanode in this equation an Ereduction or Eoxidation value?
Eoxidation
A non-volatile solute is added to a beaker filled with water. Match the different variables to Raoult's Law (Pa = Xa Pa*)
Pa = partial pressure of water in solution
Xa = mole fraction of water in solution
Pa* = Vapor pressure of pure water
When considering equilibrium reactions, what types of species are not considered when writing the reaction constant equation
solid and liquid
When you are titrating a weak species with a strong species and have formed appreciable amounts of the weak species and it's conjugate.
What is the oxidation number of atom in it's elemental substance?
Zero
If you dissolve 1.50g of a salt in 0.250L of H2O at the temperature 277K, the osmotic pressure (π) is 0.00342 atm. What is the molar mass of the salt?
4.00 x 104 g/mol
Find Kc given that the Kp is 1.48 x 104 at 186 degrees celsius
N2 (g) + O2 (g) -> 2NO (g)
Kc = 5.55 x 105
25.00 mL of 0.200 M benzoic acid (Ka = 6.3 x 10-5) is titrated with 0.200 M NaOH. Find the pH after the addition of 12 mL of acid.
What is the purpose of a salt bridge?
To balance out charges in the anode and cathode and allow the reaction to continue.