Bab 8

An electrochemical cell was set up using iron and copper plates in molar solution of Fe2+ (aq) and Cu2+ respectively. Which one is the correct cell diagram represent?

• Fe (s) | Fe2+ (aq) || Cu2+ (aq) | Cu (s)
• Cu (s) | Cu2+ (aq) || Fe2+ (aq) | Fe (s)

The standard reduction potential, E°, at 298K for five half-cells are given below.<br />W2+ (aq) + 2e- <=> W (s) -2.38V<br />X3+ (aq) + 3e- <=> X (s) -1.66V<br />Y2+ (aq) +2e- <=> Y (s) +0.34V<br />Z+ (aq) + e- <=> Z (s) +0.80V<br />Fe2+ (aq) + 2e- <=> Fe (s) -0.44V<br /><br />Which species causes iron to rust faster?<br />

• Z+
• W2+
• X3+
• Y2+

The standard reduction potential of several half-cell reactions are shown below.<br /><br />Sn2+ (aq) + 2e- -> Sn (s) -0.14V<br />Fe2+ (aq) + 2e- -> Fe (s) -0.44V<br />Cr3+ (aq) + 3e- -> Cr (s) -0.74V<br />Mn2+ (aq) + 2e- -> Mn (s) -1.18V<br />Al3+ (aq) + 3e- -> Al (s) -1.66V<br /><br />Which metal will produce the most rust when it comes in contact with iron in an electrolyte?

• Sn
• Al
• Cr
• Mn

The standard reduction potential for several half-cells at 298K are given.<br /><br />Al3+ = -1.66v,<br /><br />Fe2+ = -0.44v,<br /><br />Sn2+ = -0.14v,<br /><br />Cu2+ = +0.34v,<br /><br />I2 = +0.54,<br /><br />Fe3+ = +0.77,<br /><br />Br2 = +1.07,<br /><br />Cl2 = +1.36,<br /><br />Mn3+ = +1.49.<br /><br />Which species is the most powerful oxidising agent?

• Mn3+
• Al3+
• Cu2+
• Sn2+

Zn (s) | Zn2+ (aq) || Fe3+ (aq) , Fe2+ (aq) Pt (s). Which acts as the positive terminal?

• Pt
• Zn

Zn (s) | Zn2+ (aq) || Fe3+ (aq) , Fe2+ (aq) Pt (s). Where the negative ions go?

• Zn / Zn2+
• Fe2+ / Pt

Zn (s) | Zn2+ (aq) || Fe3+ (aq) , Fe2+ (aq) Pt (s). What happens to the [Fe2+] / [Fe3+]?

• Increases.
• Decreases.

An electrochemical cell consist of Ag+ (aq) | Ag (s) = +0.80 V, and Zn2+ (aq) | Zn (s) = -0.76 V. Where the anions from the salt bridge go?

• Ag+ (aq) | Ag (s) half-cell. 
• Zn2+ (aq) | Zn half-cell. 

An electrochemical cell consist of Ag+ (aq) | Ag (s) = +0.80 V, and Zn2+ (aq) | Zn (s) = -0.76 V. Which has a greater tendency to form positively charged ions?

• Zn
• Ag

An electrochemical cell consist of Ag+ (aq) | Ag (s) = +0.80 V, and Zn2+ (aq) | Zn (s) = -0.76 V. Which electrode acts as the anode?

• Zn
• Ag