/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 28 (a) Which electrode of a voltaic... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 20: Problem 28

(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? (c) What is special about a standard cell potential?

Short Answer

Expert verified
(a) In a voltaic cell, the anode has a higher potential energy for electrons compared to the cathode, as it is the source of electrons and they flow towards the cathode. (b) The unit of electrical potential is the volt (V). It is related to energy in joules (J) using the formula \(E = Q * V\), where E is the energy, Q is the charge, and V is the electrical potential. (c) A standard cell potential (\(E^0\)) represents the cell potential under standard conditions (298 K temperature, 1 atm pressure, and 1 M concentration for all aqueous species). It indicates the spontaneous nature of a cell reaction under these conditions.

Step by step solution

01

(a) Cathode or Anode: Higher Potential Energy for Electrons

In a voltaic cell, the anode is the electrode where the oxidation reaction occurs, while the cathode is the electrode where the reduction reaction occurs. Electrons are released at the anode as oxidation takes place and are then transferred to the cathode where reduction takes place. Since the anode is the source of electrons and they flow towards the cathode, the anode has a higher potential energy for electrons compared to the cathode.
02

(b) Units for Electrical Potential and Relation to Energy in Joules

The unit of electrical potential is the volt (V), named after Alessandro Volta. It measures the potential energy per unit charge and can be defined as the work done to move a unit charge from one point to another in an electric field. The relation between electrical potential and the energy in joules (J) can be shown using the formula: \[E = Q * V\] where E is the energy in joules, Q is the charge in coulombs (C), and V is the electrical potential in volts. Therefore, 1 volt can be defined as the potential difference across which 1 coulomb of charge gains or loses 1 joule of energy.
03

(c) Standard Cell Potential

A standard cell potential, denoted as \(E^0\), is the cell potential under standard conditions, which means a temperature of 298 K (25鈩�), a pressure of 1 atm, and a concentration of 1 M for all the aqueous species involved in the half-cell reactions. The standard cell potential can provide valuable information about the spontaneous nature of a cell reaction. If it is positive, the cell reaction will spontaneously occur under standard conditions. On the other hand, if it is negative, the cell reaction will not occur spontaneously under standard conditions.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

This oxidation-reduction reaction in acidic solution is spontaneous: \(5 \mathrm{Fe}^{2+}(a q)+\mathrm{MnO}_{4}^{-}(a q)+8 \mathrm{H}^{+}(a q)-\rightarrow\) \(5 \mathrm{Fe}^{3+}(a q)+\mathrm{Mn}^{2+}(a q)+4 \mathrm{H}_{2} \mathrm{O}(l)\) A solution containing \(\mathrm{KMnO}_{4}\) and \(\mathrm{H}_{2} \mathrm{SO}_{4}\) is poured into one beaker, and a solution of \(\mathrm{FeSO}_{4}\) is poured into another. A salt bridge is used to join the beakers. A platinum foil is placed in each solution, and a wire that passes through a voltmeter connects the two solutions. (a) Sketch the cell, indicating the anode and the cathode, the direction of electron movement through the external circuit, and the direction of ion migrations through the solutions. (b) Sketch the process that occurs at the atomic level at the surface of the anode. (c) Calculate the emf of the cell under standard conditions. (d) Calculate the emf of the cell at \(298 \mathrm{~K}\) when the concentrations are the following: \(\mathrm{pH}=0.0, \quad\left[\mathrm{Fe}^{2+}\right]=0.10 \mathrm{M}, \quad\left[\mathrm{MnO}_{4}^{-}\right]=1.50 \mathrm{M}\) \(\left[\mathrm{Fe}^{3+}\right]=2.5 \times 10^{-4} \mathrm{M},\left[\mathrm{Mn}^{2+}\right]=0.001 \mathrm{M}\)

A voltaic cell is constructed with two \(\mathrm{Zn}^{2+}-\) Zn electrodes. The two cell compartments have \(\left[\mathrm{Zn}^{2+}\right]=1.8 \mathrm{M}\) and \(\left[\mathrm{Zn}^{2+}\right]=1.00 \times 10^{-2} \mathrm{M}\), respectively. (a) Which electrode is the anode of the cell? (b) What is the standard emf of the cell? (c) What is the cell emf for the concentrations given? (d) For each electrode, predict whether \(\left[\mathrm{Zn}^{2+}\right]\) will increase, decrease, or stay the same as the cell operates.

If the equilibrium constant for a one-electron redox reaction at \(298 \mathrm{~K}\) is \(8.7 \times 10^{4}\), calculate the corresponding \(\Delta G^{\circ}\) and \(E_{\text {cell }}^{0}\)

A voltaic cell utilizes the following reaction: $$ 2 \mathrm{Fe}^{3+}(a q)+\mathrm{H}_{2}(g) \rightarrow \rightarrow 2 \mathrm{Fe}^{2+}(a q)+2 \mathrm{H}^{+}(a q) $$ (a) What is the emf of this cell under standard conditions? (b) What is the emf for this cell when \(\left[\mathrm{Fe}^{3+}\right]=2.50 \mathrm{M}\), \(P_{\mathrm{H}_{2}}=0.85 \mathrm{~atm},\left[\mathrm{Fe}^{2+}\right]=0.0010 M\), and the \(\mathrm{pH}\) in both compartments is \(5.00 ?\)

(a) \(\mathrm{A} \mathrm{Cr}^{3+}(a q)\) solution is electrolyzed, using a current of \(7.60 \mathrm{~A}\). What mass of \(\mathrm{Cr}(s)\) is plated out after \(2.00\) days? (b) What amperage is required to plate out \(0.250 \mathrm{~mol} \mathrm{Cr}\) from a \(\mathrm{Cr}^{3+}\) solution in a period of \(8.00 \mathrm{~h}\) ?
See all solutions

Recommended explanations on Chemistry Textbooks

Inorganic Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Organic Chemistry

Read Explanation

The Earths Atmosphere

Read Explanation

Kinetics

Read Explanation

Chemical Analysis

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.