Ch.20 - Electrochemistry

Problem 44a

Chapter 20, Problem 44a

Sketch a voltaic cell for each redox reaction. Label the anode and cathode and indicate the half-reaction that occurs at each electrode and the species present in each solution. Also indicate the direction of electron flow. a. Ni²⁺(aq) + Mg(s) → Ni(s) + Mg²⁺(aq)

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Identify the oxidation and reduction half-reactions. Oxidation occurs when a species loses electrons, and reduction occurs when a species gains electrons.

For the given reaction, determine which species is oxidized and which is reduced. Mg(s) is oxidized to Mg^{2+}(aq), and Ni^{2+}(aq) is reduced to Ni(s).

Write the half-reactions: Oxidation at the anode: Mg(s) \rightarrow Mg^{2+}(aq) + 2e^{-}. Reduction at the cathode: Ni^{2+}(aq) + 2e^{-} \rightarrow Ni(s).

Label the anode and cathode in the voltaic cell. The anode is where oxidation occurs (Mg(s)), and the cathode is where reduction occurs (Ni^{2+}(aq)).

Indicate the direction of electron flow. Electrons flow from the anode to the cathode through the external circuit.

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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 from spontaneous redox reactions into electrical energy. It consists of two electrodes: the anode, where oxidation occurs, and the cathode, where reduction takes place. The flow of electrons from the anode to the cathode through an external circuit generates electric current.

Redox Reactions

Redox reactions involve the transfer of electrons between two species, resulting in changes in their oxidation states. In these reactions, oxidation refers to the loss of electrons, while reduction refers to the gain of electrons. Understanding the half-reactions for each component is crucial for identifying which species is oxidized and which is reduced in a given reaction.

Electron Flow and Electrode Reactions

In a voltaic cell, electrons flow from the anode to the cathode through an external circuit. The half-reaction at the anode involves the oxidation of a species, while the half-reaction at the cathode involves the reduction of another species. Identifying the direction of electron flow and the specific half-reactions at each electrode is essential for accurately sketching the cell and understanding its operation.

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Sketch a voltaic cell for each redox reaction. Label the anode and cathode and indicate the half-reaction that occurs at each electrode and the species present in each solution. Also indicate the direction of electron flow. a. Ni2+(aq) + Mg(s) → Ni(s) + Mg2+(aq)

Verified video answer for a similar problem:

Key Concepts

Voltaic Cell

Redox Reactions

Electron Flow and Electrode Reactions

Sketch a voltaic cell for each redox reaction. Label the anode and cathode and indicate the half-reaction that occurs at each electrode and the species present in each solution. Also indicate the direction of electron flow. a. Ni²⁺(aq) + Mg(s) → Ni(s) + Mg²⁺(aq)