Question

Using the following portion of the activity series for oxidation half reactions

K(s) → K+ (aq) + e-

Al(s) → Al3+ (aq) + 3e-

Fe(s) → Fe2+ (aq) + 2e-

Sn(s) → Sn2+ (aq) + 2e-

Determine which reaction will occur.

A) Al3+(aq) with Fe(s)

B) Al(s) with Sn(s)

C) K+(aq) with Fe2+(aq)

D) K(s) with Sn2+(aq)

Answer 1

ANSWER :

D) K(s) with Sn2+(aq)

Reaction 2K(s)+Sn²⁺(aq) = 2K⁺ (aq) + Sn(s)

EXPLANATION:

The Standard oxidation potentials for the given metals are as follows

K(s) → K+ (aq) + e-                         E⁰ = + 2.92 V

Al(s) → Al3+ (aq) + 3e-                   E⁰ = + 1.66 V

Fe(s) → Fe2+ (aq) + 2e-                E⁰ = + 0.44 V

Sn(s) → Sn2+ (aq) + 2e-                E⁰ = + 0.15 V

A metal with a higher oxidation potential can reduce the ion of a metal with lesser oxidation potenial.

D)Thus K(s) can reduce Sn2+(aq) to Sn(s) .( It can also reduce Al3+ (aq) and Fe2+ (aq)

A) Fe(s) is below Al(s) in the activity series for oxidation half reactions. Hence Fe(s)cannot reduce Al3+(aq)

B) Al(s) and Sn(s) are both metals .So they will not react with each other

C) K+(aq) and Fe2+(aq) are both ions .So they will not react with each other.