Keq
Calculate the value of [N2]eq if [H2] =0.2M, [NH3] = 0.5M and Kc= 2
N2 (g) + 3H2 -> 2NH3
Why can't we say that a spontaneous reaction is a fast reaction?
The speed of a reaction is not related to the spontaneity. A spontaneous reaction can
be very slow.
balance: acidic cond
H3PO2 + Cr2O72- → H3PO4 + Cr3
16H+ + 3H3PO2 + 2Cr2 O72- → 3H3PO4 + 4Cr3+ + 8H2O
Based on the following information,
Cl2(g) + 2 e- → 2 Cl-(aq) E° = +1.36 V
Mg2+(aq) + 2 e- → 2 Mg(s) E° = -2.37 V
Identify the strongest reducing agent?
Mg (s) because when it is a reducing agent it has the highest E cell.
A voltaic cell has a standard cell potential equal to 0.74 V. If the standard reduction potential for the anode is -.22V what is the standard electrode potential for the cathode?
0.52V
Which of the following statements is TRUE?
A) If Q < Keq, it means the reverse reaction will proceed to form more reactants.
B) If Q > Keq, it means the forward reaction will proceed to form more products.
C) If Q = Keq, it means the reaction is at equilibrium.
D) All of the above are true.
E) None of the above are true
C
Choose the statement below that is TRUE.
A) Keq > 1, ΔG°rxn is positive.
B) Keq < 1, ΔG°rxn is negative.
C) ΔG°rxn = 0 at equilibrium.
D) ΔGrxn = 0 at equilibrium.
E) None of the above statements are true.
D
What is the difference between balancing redox reactions in acidic and basic solutions
Basic solutions will add an equivalent # of H+ using OH- to both sides. Then each H+ and OH- will make H2O
The cell notation Al(s)/Al3+(aq)//Co2+(aq)/Co(s) indicates that,
A) Co(s) oxidizes
B) Co2+ oxidizes
C) Al(s) oxidizes
D) Al3+ reduces
E) Al(s) reduces
Al(s) oxidizes
Will this reaction be spontaneous?
Ag(s)+Fe3+(aq)→Ag+(aq)+Fe2+(aq)\text{Ag(s)} + \text{Fe}^{3+}(aq) \rightarrow \text{Ag}^{+}(aq) + \text{Fe}^{2+}(aq)Ag(s)+Fe3+(aq)→Ag+(aq)+Fe2+(aq)
Given:
Fe³⁺ + e⁻ → Fe²⁺ E° = +0.77 V
Ag⁺ + e⁻ → Ag(s) E° = +0.80 V
E is negative so no
Determine the value of Kc for the following reaction if the equilibrium concentrations are as
follows: [HCl]eq = 0.13 M, [HI]eq = 5.6 × 10-16 M, [Cl2]eq = 0.0019 M.
2 HI(g) + Cl2(g) ⇌ 2 HCl(g) + I2(s)
2.8 × 10^31
What is true if ln(Keq) is negative?
A) ΔGorxn is positive and the reaction is product favored.
B) ΔGorxn is negative and the reaction is product favored.
C) ΔGorxn is negative and the reaction is reactant favored.
D) ΔGorxn is positive and the reaction is reactant favored.
E) ΔGorxn is zero and the reaction is at equilibrium.
d
Predict the species that will be reduced first
Zn2+, Fe3+, Mg2+, Br-, I-
A) Zn2+ B) Mg2+ C) Br- D) Fe3+ E) I-
D) Fe3+ because it has the highest E cell.
What is the balanced chemical equation for the galvanic cell reaction expressed using shorthand
notation below?
Al(s) ∣ Al3+(aq) ∣∣ Fe2+(aq) ∣ Fe(s)
2 Al(s) + 3 Fe2+(aq) → 2 Al3+(aq) + 3 Fe(s)
Will this reaction occur spontaneously?
Zn(s)+Cu2+(aq)→Zn2+(aq)+Cu(s)\text{Zn(s)} + \text{Cu}^{2+}(aq) \rightarrow \text{Zn}^{2+}(aq) + \text{Cu(s)}Zn(s)+Cu2+(aq)→Zn2+(aq)+Cu(s)
Given:
Cu²⁺ + 2e⁻ → Cu(s) E° = +0.34 V
Zn²⁺ + 2e⁻ → Zn(s) E° = –0.76 V
Yes E=1.10V
The equilibrium constant Kc fro the following reaction is known to be 0.141 at 25 C.
2BrCl(g) -> BR2(g) + Cl2(g)
If the initial concentrations of Br2 and Cl2 are 0.1M and the initial concentration of BrCl is 0.2M what are the equilibrium concentrations of all species?
Br2 and Cl2 is 0.0858M
BrCl + 0.228M
Use the free energies of formation given below to calculate the equilibrium constant (Keq) for the
following reaction at 298 K.
2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l) K = ?
ΔG°f (kJ/mol) -110.9 87.6 51.3 -237.1
1.15 x 10^-9
What is the value of the equilibrium constant for the redox reaction below at 25C that happens in acidic conditions?
MnO4-(aq) + Pb2+(aq) <-> Mn2+(aq) + PbO2(s)
286,051 KJ
A voltaic cell consists of a peice of Mn (s) immersed in Mn2+(aq) electrode (E= -1.18V) and a piece of Fe(s) immersed in Fe2+ electrode (E=-.44V). Calculate Fe2+ concentration if [Mn2+] is 0.05M and E cell is .78V at 25c.
1.127M
The standard voltage output for the cell using the overall cell reaction below is +.48V:
Zn (s) + Ni2+(aq) -> Zn2+(aq) + Ni (s)
The voltage generated by the cell when [Ni2+]= 2.5M and [Zn2+] = .100M
0.52
Consider the equilibrium: 2ICl(g) = I2 (g) + Cl2 (g) Keq= 10.0
If x moles of ICl were placed in a 5.0 L container at 10 oC and if an equilibrium concentration of I2 was found to be 0.60 M, calculate the
number of moles ICl initially present
6.9 mols
See powerpoint
blebleh
Determine the rate law and the value of k for the following reaction using the data provided.
NO2(g) + O3(g) → NO3(g) + O2(g)
[NO2]i [O3]i [initial rate]
0.10 0.33 1.42
0.10 0.66 2.84
0.25 0.66 7.10
43 M-1s-1[NO2][O3]
Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction
occurring in an electrochemical cell at 25°C. (The equation is balanced.)
Pb(s) + Br2(l) → Pb2+(aq) + 2 Br⁻(aq)
Pb2+(aq) + 2 e⁻ → Pb(s) E° = -0.13 V
Br2(l) + 2 e⁻ → 2 Br⁻(aq) E° = +1.07 V
A
Which half reactions have the strongest reducing agent among the following species?
Co2+ + 2e- <-> Co(s) Ecell = -0.28 V
Fe2+(aq) + 2e- <-> Fe (s) Ecell = -0.45 V
Cr2+ (aq) + 2e- <-> Cr (s) Ecell = -0.92 V
Sr2+ (aq) + 2e- <-> Sr (s) Ecell = -2.89 V
A) Co(s) B)Co2+ C) Sr(s) D) Sr2+
C) Sr(s)