Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 21: Q21.28 P (page 973)

A voltaic cell is constructed with anAg/Ag+half-cell and aPb/Pb2 +half-cell. The zinc electrode is negative.

(a) Write balanced half-reactions and the overall reaction.

(b) Diagram the cell, labeling electrodes with their charges and showing the directions of electron flow in the circuit and of cation and anion flow in the salt bridge.

Short Answer

Expert verified

(a)Oxidation :Sn→Sn2 ++ 2e-Reduction :Zn2 ++ 2e-→ZnOverall :Sn + Zn2 +→Zn + Sn2 +

(b) Electrons travel from the anode to the cathode, while anions and cations flow from the cathode to the anode. The cathode is the Zn electrode, and the anode is the Sn electrode.

Step by step solution

01

Definition of Chemical Change and Electrical Work

Electrochemistry is a discipline of physical chemistry concerned with the relationship between electrical potential as a quantifiable and quantitative phenomena and recognizable chemical change, with electrical potential as an outcome of a specific chemical change or vice versa.

02

Write balanced half-reactions and the overall reaction.

  1. Half-reactions that are balanced, as well as the overall reaction

Oxidation :Ag→Ag++e-Reduction :Pb2 ++ 2e-→PbOverall:2Ag + Pb2 +→Pb + Ag+

03

Diagram the cell, labeling electrodes with their charges and showing the directions

(b) Electrons travel from the anode to the cathode, while anions and cations flow from the cathode to the anode.

The cathode is a Pb electrode, and the anode is an Ag electrode.

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.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

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

Magnesium bars are connected electrically to underground iron pipes to serve as sacrificial anodes.

(a) Do electrons flow from the bar to the pipe or the reverse?

(b) A12kgMgbar is attached to an iron pipe, and it takes8.5 yrfor the Mgto be consumed. What is the average current flowing between the Mgand the Feduring this period?

A voltaic cell with Ni/Ni2and Co/C half-cells has the following initial concentrations[Ni2 +]= 0.80M;[Co2 +]=0.20M.

(a) What is the initialEcell?

(b) What is[Ni+ 2] whenEcellreaches 0.03V?

(c) What are the equilibrium concentrations of the ions?

Which of the following metals are suitable for use as sacrificial anodes to protect against corrosion of underground iron pipes? If any are not suitable, explain why:

(a) Aluminium

(b) Magnesium

(c) Sodium

(d) Lead

(e) Nickel

(f) Zinc

(g) Chromium

Comparing the standard electrode potentials (Eo)of the Group 1A(1)metalsLi, Na, and Kwith the negative of their first ionization energies reveals a discrepancy:

Ionization process reversed:M+(g) +e-⇌M(g) ( - IE)

Electrode reaction:M+(aq) +e-⇌M(s) (Eo)

Note that the electrode potentials do not decrease smoothly down the group, as the ionization energies do. You might expect that if it is more difficult to remove an electron from an atom to form a gaseous ion (largerIE), then it would be less difficult to add an electron to an aqueous ion to form an atom (smallerEo), yetLi+(aq)is more difficult to reduce thanNa+(aq). Applying Hess’s law, use an approach similar to that for a Born-Haber cycle to break down the process occurring at the electrode into three steps and label the energy involved in each step. How can you account for the discrepancy?

Commercial aluminium production is done by the electrolysis of a bath containingAl2O3dissolved in molten Na3AlF6salt. Why isn’t it done by electrolysis of an aqueousAlCl3solution?
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

Kinetics

Read Explanation

Physical Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Making Measurements

Read Explanation

Chemical Reactions

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.

Sign-up for free