Target: 10 Questions in 10 minutes

An IB Chemistry data booklet is helpful
1. Calculate the overall cell potential for the following voltaic cell.

Cu(s)|Cu2+(aq)||Fe3+(aq), Fe2+(aq)|Pt

  • A.   0.25 V
  • B.   0.43 V
  • C.   0.79 V
  • D.   1.20 V

2. A voltaic cell is made from the following two half-cells, which of the following acts as the anode of the cell?

Ni2+(aq) + 2e- ⇌ Ni(s) -0.26 V
Mn2+(aq) + 2e- ⇌ Mn(s)    -1.18 V
 
  • A.   Ni(s)
  • B.   Ni2+(aq)
  • C.   Mn(s)
  • D.   Mn2+(aq)

3. Which of the following reactions is spontaneous, if they are all carried out at standard conditions?

I. Cr2O7 2-(aq) + 6F -(aq) + 14H +(aq)  →  2Cr 3+(aq) + 3F2(g) + 7H2O(l)
II. 2Fe 3+(aq) + 2I -(aq)  →  2Fe 2+(aq) + I2(s)
III. 3Cl2(l) + 2Al(s)  →  2AlCl3(s)
  • A.   I only
  • B.   I and II only
  • C.   I and III only
  • D.   II and III only
4. What is the standard cell potential for the V2+(aq), V3+(aq) half-cell if the overall cell potential for the voltaic cell Pt|V2+(aq), V3+(aq)||Cr2O72-(aq), Cr3+(aq)|Pt is 1.62 V?
  • A.  -1.10 V
  • B.  -0.26 V
  • C.   0.26 V
  • D.   2.98 V

5. What is the ΔGo for the following reaction:

ClO3-(aq) + 5Cl-(aq) + 6H-(aq) → 3Cl2(aq) + 3H2O(l)

given that ..

12H+(aq) + 2ClO3-(aq) + 10e- ⇌ Cl2(aq) + 6H2O           Eo = 1.47 V
 
  • A.   -1370 kJ
  • B.   -106 kJ
  • C.   -53 kJ
  • D.   +106 kJ

6. For the voltaic cell Zn(s)|Zn2+(aq)||Cu2+(aq)|Cu(s), which of the following changes will increase the cell potential?          

I. Increasing the concentration of Cu2+(aq)
II. Diluting the Zn2+ aqueous solution
III. Remove the salt bridge
  • A.   I and II only
  • B.   I and III only
  • C.   II and III only
  • D.   I, II and III

Q7-10: Use the following standard electrode potentials to answer these questions:

Zn2+(aq) + 2e−  ⇌  Zn(s) Eo = -0.76 V
Cr3+(aq) + 3e−  ⇌  Cr(s) Eo = -0.74 V
Fe2+(aq) + 2e−  ⇌  Fe(s)  Eo = -0.45 V
Cr3+(aq) + e−  ⇌  Cr2+(aq)    Eo = -0.41 V
V3+(aq) + e−  ⇌  V2+(aq)  Eo = -0.26 V
Cu2+(aq) + 2e−  ⇌  Cu(s)  Eo = +0.34 V
7. Which species in the table is the strongest oxidising agent?
  • A.   Zn(s)
  • B.   Zn2+(aq)
  • C.   Cu(s)
  • D.   Cu2+(aq)
8. Which two species in the table can reduce Cr3+(aq) to Cr2+(aq)?
  • A.   V2+(aq) and Cu(s)
  • B.   Zn(s) and Fe(s)
  • C.   Zn2+(aq) and Fe2+(aq)
  • D.   V3+(aq) and Cu2+(aq)
9. Which species in the table can oxidise Cr(s) to Cr3+(aq) but cannot oxidise Cr2+ (aq) to Cr3+(aq) under standard conditions?
  • A.  Zn2+(aq)
  • B.  Fe2+(aq)
  • C.  V2+(aq)
  • D.  Cu2+(aq)
10. Which of the following reactions is the most spontaneous under standard conditions?
  • A.   Zn2+(aq) + 2V2+(aq) → Zn(s) + 2V3+(aq)
  • B.   2Cr3+(aq) + Zn(s) → 2Cr2+(aq) + Zn2+(aq)
  • C.   3V3+(aq) + Cr(s) → 3V2+(aq) + Cr3+(aq)
  • D.   Cu2+(aq) + Fe(s) → Fe2+(aq) + Cu(s)