Which of the following redox conditions will produce a spontaneous reaction? A. The voltage of the reduction half-reaction is negative.
B. The voltage of the reduction half-reaction is positive.
C. The sum of the voltages of the half-reactions is negative.
D. The sum of the voltages of the half-reactions is positive.

What diagram shows the ionic compound of magnesium oxide

Frictional forces acting on an object are often converted into energy, which causes the temperature of the object to rise slightly.

Consider the reduction reactions and their equilibrium constants. cu+(aq)+e−↽−−⇀cu(s)pb2+(aq)+2e−↽−−⇀pb(s)fe3+(aq)+3e−↽−−⇀fe(=6.2×108=4.0×10−5=9.3×10−3 cu + ( aq ) + e − ↽ − − ⇀ cu ( s ) k =6.2× 10 8 pb 2 + ( aq ) +2 e − ↽ − − ⇀ pb ( s ) k =4.0× 10 − 5 fe 3 + ( aq ) +3 e − ↽ − − ⇀ fe ( s ) k =9.3× 10 − 3 arrange these ions from strongest to weakest oxidizing agent.