Kinetics
The correct rate expression for A in the equation:
2A + B → A2B
-[A]/2∆t
The proper equilibrium expression for:
H2O (l) ↔ 2H2(g) + O2(g)
K= [H2]2[O2]
pH=pKa + log(B/A)
pOH=pKb + log(A/B)
Identify the oxidizing and reducing agent
Cu(s) + 2Ag+ (aq) ↔ Cu2+ (aq) + 2Ag(s)
Cu(s) is the reducing agent
2Ag+(aq) is the oxidizing agent
What are your 6 strong acids and 6 strong bases?
*You must have all of them for the credit*
Acids: H2SO4, HI, HBr, HNO3, HCl, HClO4
Bases: LiOH, NaOH, KOH, Ca(OH)2, Sr(OH)2, Ba(OH)2
The rate constant of a first-order decomposition reaction is 0.0258 s-1. If the initial reactant concentration is 1.250M, what is the concentration of the reactant after 25 seconds? ***ln([R]f/[R]i)=-kt***
0.656M
Given: 4NH3 (g) + 3O2 (g) ↔ 2N2 (g) + 6H2O (l)
What direction will the equilibrium shift if some oxygen is added?
If the Ka of a compound is 2.85 x 10-6 , what is its pKb?
8.45
For a reaction, ∆H = -200kJ and ∆S° = -300J/K*mol. At what temperature will ∆G° = 0 kJ/mol-rxn?
T=666.67K
What is E°cell for the reaction
Sn (s) + 2Cu2+ (aq) ↔ Sn2+(aq) + 2Cu+(aq) using the following reduction potentials:
Sn2+ (aq) + 2e- ↔ Sn (s) E° = -0.1375V
Cu2+ + e- ↔ Cu+ E° = 0.153V
E°cell=0.2905V
Determine the average rate of formation of C in the equation A + 3B → 2C, from the 5 to 15-second interval using the table below:
Time (s) [B] (M)
0.0 3.00
5.0 2.85
10.0 2.10
15.0 1.26
0.053
Which of the following is the strongest acid?
A. Cyanic Acid Kb = 3.5 x 10-4
B. Benzoic Acid Kb = 6.3 x 10-5
C. Ethanoic Acid Kb = 1.8 x 10-5
D. Nitrous Acid Kb = 7.2 x 10-4
B. Benzoic Acid Kb = 6.3 x 10-5
What is the pH of a buffer composed of 0.30M H2PO4- (aq) and 0.60M HPO42- (aq)? Ka of H2PO4- is 6.2 x 10-8?
pH=7.51
Calculate the standard entropy change for the following reaction:
2NO (g) + O2 (g) → 2NO2 (g)
(S◦ values: NO = 210.8 J/K*mol, O2 = 205.1 J/K*mol, NO2 = 240.0 J/K*mol)
standard entropy change=-146.7J/K*mol
The hydroxide ion concentration of a saturated solution of Ba(OH)2 is 3.50 x 10-2. What is the solubility product constant for Ba(OH)2?
Ksp=2.14x10-5
What is the correct experimental rate law:
Experiment: Initial Rate: [A]: [B]:
1 0.15 0.22 0.15
2 1.35 0.22 0.45
3 0.64 0.44 0.15
Rate=k[A]2[B]2
What is the hydronium ion concentration of a 0.50M solution of hydrocyanic acid (HCN) if the Ka at room temperature is 4.9 x 10-10?
1.56x10-5M
What is the pOH of a saturated solution of Ca(OH)2? (Kw = 1.0 x 10-14, Ksp = 5.5 x 10-5)
pOH=1.32
The standard free energy change associated with the dissolution of ammonium nitrate
(NH4NO3) in water is -6.73kJ/mol at 298K.
What is the equilibrium constant?
K=15.12
Here is a fun one for a challenge:
see if you can determine the product for each step
when 23892 𝑈 undergoes the following successive decays: αββααα (alpha-beta-beta-
alpha-alpha-alpha
alpha→ 23490Th
beta→ 23491Pa
beta→ 23492U
alpha→ 23090Th
alpha→ 22688Rn
alpha→ 22286Po
The half-life for a reactant that follows first-order kinetics is 75 seconds. How long would it take for the concentration of the reactant to decrease by 15%?
17.5s
What is the pH of a 0.50M solution of sodium acetate (NaC2H3O2) if the Ka of acetic acid is 1.8 x 10-5?
10.81
You have 50mL of 0.15M HA, a weak acid. After adding 25mL of 0.05M KOH, the pH is 6.50. What is the Ka value for HA?
Ka=6.3x10-8
For the cell reaction:
Zn (s) + 2H+ (aq) ↔ Zn2+ (aq) + H2 (g),
what is the concentration of H+ if the voltage is 0.45V at 25°C and [Zn2+] is 1.0M?
Zn2+ (aq) + 2e- ↔ Zn (s) E°= -0.763
2H+ (aq) + 2e- ↔ H2 (g) E°= 0
[H+]=5.14x10-6M
For a solution made when 150mL of 0.150M HCl is added to 150mL of 0.500M NH3 (Kb for NH3 = 1.8 x 10-5) find the pH
pH=4.37