Consider the following standard reduction potentials of some commonly used metal

Question

Consider the following standard reduction potentials of some commonly used metals:

Using the reduction potentials one can compare the reactivities of metals towards oxidation- reduction processes. Evaluate the following statements and determine if they are True or False.
TrueFalse Fe3+ (aq) can oxidize Al (s).
TrueFalse A positive reduction potential means that the metal is more stable in its ionic state (aq) than in its reduced state (s).
TrueFalse Elemental aluminum (Al (s)) is more stable than elemental iron (Fe (s)).
TrueFalse Aluminum has a strong tendancy to be reduced and is therefore a precious metal.
TrueFalse Ag (s) can be oxidized by Al3+ (aq).

?o (V) Au3+ (aq) + 3 e- ? Au (s) +1.50 Ag+ (aq) + e- ? Ag (s) +0.80 Cu2+ (aq) + 2e- ? Cu (s) +0.34 Fe3+ (aq) + 3e- ? Fe (s) -0.036V Al3+ (aq) + 3e- ? Al (s) -1.66 Mg2+ (aq) + 2e- ? Mg (s) -2.37

Explanation / Answer

1) True

Fe+3 + AL ---------> Al+3 + Fe

Ecell = -0.036 +1.66 = +1.624

As th eE cell is positive , the reaction occurs, that is Fe+3 can oxidise Al or in other words Al can reduce Fe+3 to Fe.

2) False

A positive reduction potential means, the metal ion readily reduces to metal, that is ionic state is less stable than reduced state.

3) False

Al is more reactive and easily oxidised by Fe+3 .[same eplanation as 1]

4) False

Al has strong tendency to get oxidised to Al+3

5) False

3Ag + Al+3 ---------->3 Ag+ + AL

For this reaction to occur Ecell = -0.80 -1.66

= - 2.46 V

As the E cell is negative this reaction does not occur.

Rather Al is oxidised by Ag+.

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---