Acids/Bases I
Arrhenius definition of a base
substance that increases concentration of hydroxide ion in water
Kc = 1.5 x 1032, what does equilibrium favor?
Products
What happens to the oxidation number of a species if it is reduced?
oxidation number gets smaller
Water flowing downhill is an example of a spontaneous or nonspontaneous process
spontaneous
Given the following reaction and rate law
2A + 3B ---> 2C + D
r = k[A]2[B]
What is the overall reaction order
3rd Order
If Ka for acetic acid is 1.8 x 10-5, what is Kb
5.6 x 10-10
If Q > K, which way does the reaction proceed towards equilibrium?
Towards Reactants
In an electrochemical cell, where does oxidation occur
anode
What is entropy?
- measure of disorder or randomness
- measure of how energy can be spread around a system
Given the following reaction and rate law
2A + 3B ---> 2C + D
r = k[A]2
What is the effect of doubling concentration B?
Doubling A?
When [B] is doubled, there is no effect
When [A] is doubled, rate quadruples
What is the pH of a 0.421 M Ba(OH)2 solution
13.93
Consider the dissolution of CaF2 in water where [F]=0.5M by addition of NaF before CaF2 was added. How will the dissolution of CaF2 be effected?
dissolution will be suppressed via the common ion effect
If E standard = 1.07V and n = 4 e- for a particular reaction, what is delta G standard in kJ?
-413 kJ
What can be said about a system when delta G=0
at equilibrium
*Question 1
r = k[NO]2[Br2]
What is the pH of a 2.01M solution of ammonia? Kb=1.8x10-5
pH = 11.78
For the following reaction at 2000 degrees C, what is the equilibrium partial pressure of Br2 if the initial partial pressure of IBr is 0.25 atm and there are no products initially
2IBr -----> I2 + Br2 Kp = 8.5 x 10-3
0.0195
What is the sum of the stoichiometric coefficients of the balanced redox reaction in acidic conditions? H2O2 is hydrogen peroxide
MnO4- + H2O2 ---> Mn2+ + O2
28
What is the sign of delta S for the reaction below
PCl3 + Cl2 ---> PCl5
negative
What are the intermediates of the following mechanism
1. HBr + O2 ---> HOOBr
2. HOOBr +HBr ---> 2HOBr
3. HOBr +HBr ---> H2O +Br2
4. HOBr +HBr ---> H2O +Br2
HOOBr and HOBr
What is the pH of a buffer solution that is 0.971M HNO2 and 1.25M NaNO2? The Ka of HNO2 is 4.5 x 10-4
pH = 3.46
For the following reaction at equilibrium
2SO2 + O2 ----> 2SO3, what is the effect of adding 10 mol Xenon gas?
No effect
For the following batter E standard = 2.041V, what is E at -40 degrees C and [H2SO4]=0.01M
Pb + PbO2 + 2H2SO4 ---> 2PbSO4 + 2H2O
1.949 V
For the reaction below, calculate delta H standard and delta S standard. Then calculate delta G standard at 298K and comment on the spontaneity
NO2 + N2O ---> 3NO
delta S standard = 171.41 J/K
delta H standard = 155.67 kJ
delta G standard = 104.6 kJ
nonspontaneous at 298K
A reaction is zero order with respect to reactant A and has a rate constant of 2.51 x 10-2 M/s. If initial [A]=0.23M, how long will it take for [A]=0.001M
9.1 sec