A voltaic cell consists of a strip of cadmium metal in a solution of Cd(NO3)2 in one beaker, and in the other beaker a platinum electrode is immersed in a NaCl solution, with Cl2 gas bubbled around the electrode. A salt bridge connects the two beakers. (a) Which electrode serves as the anode, and which as the cathode? (b) Does the Cd electrode gain or lose mass as the cell reaction proceeds? (c) Write the equation for the overall cell reaction.
Verified step by step guidance
1
Identify the oxidation and reduction half-reactions. In the cadmium beaker, cadmium will undergo oxidation, losing electrons. In the platinum electrode beaker, chlorine gas (Cl2) will undergo reduction, gaining electrons.
Write the half-reaction for the cadmium electrode: Cd(s) → Cd^{2+}(aq) + 2e^{-}. This indicates that cadmium metal is oxidized to cadmium ions while releasing two electrons.
Write the half-reaction for the platinum electrode: Cl2(g) + 2e^{-} → 2Cl^{-}(aq). This shows that chlorine gas is reduced to chloride ions by gaining two electrons.
Combine the two half-reactions to form the overall cell reaction. Ensure that the number of electrons lost in the oxidation half-reaction equals the number of electrons gained in the reduction half-reaction.
The overall cell reaction is: Cd(s) + Cl2(g) → Cd^{2+}(aq) + 2Cl^{-}(aq). This equation represents the net process occurring in the voltaic cell, where cadmium is oxidized and chlorine is reduced.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
6m
Play a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Voltaic Cell
A voltaic cell, also known as a galvanic cell, is an electrochemical cell that converts chemical energy into electrical energy through spontaneous redox reactions. It consists of two half-cells, each containing an electrode and an electrolyte, connected by a salt bridge that allows ion flow while preventing the mixing of different solutions.
Oxidation and reduction are fundamental concepts in redox reactions. Oxidation refers to the loss of electrons by a substance, while reduction refers to the gain of electrons. In a voltaic cell, one electrode undergoes oxidation (anode) and the other undergoes reduction (cathode), leading to the flow of electrons through an external circuit.
The overall cell reaction equation represents the combined oxidation and reduction half-reactions occurring in a voltaic cell. It is derived by balancing the number of electrons lost in oxidation with those gained in reduction, resulting in a stoichiometric equation that reflects the reactants and products involved in the electrochemical process.
01:21
