Vocab.
What does supersaturated mean?
contain more solute than is possible to be dissolved
Molarity formula?
mol solute/ L solution
what is i (vant Hoff factor) in CaCl2?
2
IF A MOLECULAR COMPOUND, i=1
Molarity vs Molality?
Molarity uses the volume of the total solution, whereas molality uses the mass of the solvent
What does not affect equilibrium?
what does Homogenous mean?
a mixture of 2 or more substances in a single phase
Molality formula
mol solute/ kilograms solution
Dissolve 5.00 g of NiCl2 x 6H2O in enough water to make 250. mL of solution. Calculate molarity
0.0891
Saturated vs unsaturated
Saturated are solutions contain maximum quanity of solute that dissolve at that temperature
Unsaturated contain less than the maximum amount of solute
Which direction does an increase in concentration shift on the product side the equation
Shifts Left
minimum amount of energy that colliding particles must have in order to react
Percent by Mass
gram solute/grams solution
25.0 of NaCl is dissolved in 5000. mL of water. Find the molality (m) of the resulitng solution
0.0854 m
Entropy is a measure of randomness and enthalpy is a measure of heat
What is entropy?
measure of randomness of a system
if random goes up then entropy goes up
What is Le Chatelier's principle?
if a stress is applied to a system at equilibrium, the system will shift to relieve the stress
Dilution formula?
M1V1=M2V2
Dissolve 62.1 g of glycol (1.00 mol) in 250. g of water. What is the boiling point of the solution?
Kb=0.52 degress celcius/molal for water (USE TABLE ON PERIODIC TABLE)
use kmi
0.52 x 4.00 molal x 1= 2.08 Degrees Celcius
BP=100.0 +2.08=102.08 degrees celcius
Exergonic vs Exogonic
DOUBLE POINTS: which is spontaneous
Exergonic reactions are those that release free energy.SPONTAOUS
Exergonic reactions are those that absorb or require free energy.
How would you prepare 100 mL of 0.40 M
MgSO4 from a stock solution of 2.0 M
MgSO4?
M1V1 = M2V2
(2.0 M)(V1) = (0.40 M)(100 mL)
V1 = 20 mL
You would mix 20 mL of 2.0 M MgSO4
with 80 mL of water.
What is the collision theory?
to react and form a bond, particles must collide with enough KINETIC ENERGY (in the right orientation)
Boiling Point Elevation and Freezing point depression formula
ΔT=Kmi
N2O4 (g) ↔ 2NO2 (g)
A 2.0-liter container contains 0.0045 mol of N2O4 and
0.0030 mol of NO2 at equilibrium. Write the equilibrium constant expression and calculate the value for Keq.
Keq = [NO2]2/[N2O4]
Need [ ] (mol/L):
0.0045 mol/2.0 L = 0.0023 M
0.0030 mol/2.0 L = 0.0015 M
Solve: (0.0015)2/0.0023 = 0.00098
Keq < 1, reaction is nonspontaneous (favors reactants)
On adding a solute to a solvent, what happens to each of the following: vapor pressure, melting point, and boiling point?
VP decreases
Melting point decreases
boiling point increases
What are the Three of the Four things that affect reaction rates?
temperature, concentration, particle size, and catalysts