What must be true for a spontaneous reaction in an electrochemical cell?
the overall cell potential must be positive.
the overall cell potential must be negative.
the cathode’s standard reduction potential must be positive.
the cathode’s standard reduction potential must be negative.

Each of the following reactions is allowed to come to equilibrium and then the volume is changed as indicated. predict the effect (shift right, shift left, or no effect) of the indicated volume change. drag the appropriate items to their respective bins.co(g) + h2o(g) < => co2(g) + h2(g) (volume is decreased) pcl3(g) + cl2(g) < => pcl5(g) (volume is increased) caco3(s)< => cao(s) + co2(g) (volume is increased)