(a) Which electrode of a voltaic cell, the cathode or the anode, corresponds to the higher potential energy for the electrons? (b) What are the units for electrical potential? How does this unit relate to energy expressed in joules?

Name: Chemistry: The Central Science
Author: Brown
ISBN: 9780137542970

Verified step by step guidance

Step 1: Understand the roles of the anode and cathode in a voltaic cell. The anode is where oxidation occurs, and electrons are released. The cathode is where reduction occurs, and electrons are accepted.

Step 2: Recognize that electrons flow from the anode to the cathode in a voltaic cell. This flow is due to the difference in potential energy between the two electrodes.

Step 3: Determine which electrode has higher potential energy for electrons. Since electrons move from high to low potential energy, the anode has higher potential energy for electrons compared to the cathode.

Step 4: Identify the units for electrical potential. Electrical potential is measured in volts (V).

Step 5: Relate volts to energy in joules. One volt is defined as one joule per coulomb (1 V = 1 J/C), indicating the amount of energy per unit charge.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Voltaic Cell Components

A voltaic cell consists of two electrodes: the anode and the cathode. The anode is where oxidation occurs, releasing electrons, while the cathode is where reduction takes place, accepting electrons. The cathode has a higher potential energy for electrons compared to the anode, as it is the site of electron gain, leading to a flow of electrons from the anode to the cathode.

Electrical Potential and Its Units

Electrical potential, often measured in volts (V), represents the potential energy per unit charge available to move electrons through a circuit. One volt is defined as one joule of energy per coulomb of charge. This relationship indicates that higher electrical potential corresponds to greater energy available for electron movement, which is crucial for understanding how voltaic cells operate.

Relationship Between Joules and Volts

The relationship between joules and volts is fundamental in electrical systems. Specifically, 1 volt equals 1 joule per coulomb, meaning that if a charge of one coulomb moves through an electrical potential difference of one volt, it gains one joule of energy. This connection is essential for calculating energy changes in electrochemical reactions within voltaic cells.

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Related Practice

Textbook Question

(b) Write the half-reaction that occurs at a hydrogen electrode in acidic aqueous solution when it serves as the anode of a voltaic cell.

Textbook Question

(a) What is the definition of the volt?

Textbook Question

A voltaic cell similar to that shown in Figure 20.5 is constructed. One electrode half-cell consists of a silver strip placed in a solution of AgNO3, and the other has an iron strip placed in a solution of FeCl2. The overall cell reaction is Fe1s2 + 2 Ag+1aq2 ¡ Fe2+1aq2 + 2 Ag1s2 (f) In which directions do the cations and anions migrate through the solution?

Textbook Question

(b) Do all voltaic cells produce a positive cell potential?

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