# Problem: Classify each reaction as spontaneous or nonspontaneous.Drag the appropriate items to their respective bins.Ca(s) + 2K+(aq) → Ca2+(aq) + 2K(s)3K(s) + Cr3+(aq) → 3K+(aq) + Cr(s) Cu(s) + 2Ag+(aq) → Cu2+(aq) + 2Ag(s)3Ni(s) + 2Cr3+(aq) → 3Ni2+(aq) + 2Cr(s)2Al(s) + 3Sn2+(aq) → 2Al3+(aq) + 3Sn(s)Au(s) + 3Li+(aq) → Au3+(aq) + 3Li(s)SpontaneousNonspontaneous

###### FREE Expert Solution

For Ca(s) + 2K+(aq) → Ca2+(aq) + 2K(s)

Step 1. Write the two half-cell reactions

Ca(s) → Ca2+(aq)

K+(aq) → K(s)

Step 2. Identify the oxidation half-reaction (anode) and the reduction half-reaction (cathode)

When a balanced reaction is given, identify the anode and the cathode half-reactions by determining the changes in oxidation states of each species based on the given reaction:

Recall:

Lose               Gain
Electron         Electrons
Oxidation       Reduction

cathode → reduction → oxidation number decreases

anode → oxidation → oxidation number increases

For ions: charge of the ion = oxidation number
For neutral atoms/compound: oxidation number = 0

Ca(s) → Ca2+(aq)
oxidation number increased → lost electrons → oxidized anode

K+(aq) → K(s)
oxidation number decreased reduced → cathode

Step 3. Determine the half-cell potentials (refer to the Standard Reduction Potential Table)

Ca2+(aq) + 2 e- → Ca(s)                        E°cell = – 2.76 V

K+(aq) + e- → K(s)                                    E°cell = – 2.92 V

Note that both reactions are written in the reduction half-reaction form because the reduction potentials given are for reduction half-reactions (from the standard reduction potential table). So, there’s no need to reverse the reactions or change signs.

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###### Problem Details

Classify each reaction as spontaneous or nonspontaneous.

Drag the appropriate items to their respective bins.

Ca(s) + 2K+(aq) → Ca2+(aq) + 2K(s)

3K(s) + Cr3+(aq) → 3K+(aq) + Cr(s)

Cu(s) + 2Ag+(aq) → Cu2+(aq) + 2Ag(s)

3Ni(s) + 2Cr3+(aq) → 3Ni2+(aq) + 2Cr(s)

2Al(s) + 3Sn2+(aq) → 2Al3+(aq) + 3Sn(s)

Au(s) + 3Li+(aq) → Au3+(aq) + 3Li(s)

Spontaneous

Nonspontaneous