Regents Chemistry Exam 2022
49 The diagram and ionic equation below represent an operating voltaic cell.
Which phrase describes the direction of electron flow in this cell?
(1) from Ni(s) through the wire to Mg(s)
(2) from Mg(s) through the wire to Ni(s)
(3) from Ni^2+(aq) ions through the salt bridge to Mg^2+(aq) ions
(4) from Mg^2+(aq) ions through the salt bridge to Ni^2+(aq) ions
Explanation: In a voltaic cell, electrons flow from the anode(loss of electrons) to the cathode(gain of electrons) through the wire, not salt bridge. This eliminates choices 3 and 4. The anode is usually on the left in the diagram and cathode on the right, making choice 2 the correct answer