/*! 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 29 (a) Write the half-reaction that... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 20: Problem 29

(a) Write the half-reaction that occurs at a hydrogen electrode in acidic aqueous solution when it serves as the cathode of a voltaic cell. (b) What is standard about the standard hydrogen electrode? (c) What is the role of the platinum foil in a standard hydrogen electrode?

Short Answer

Expert verified
(a) The half-reaction occurring at a hydrogen electrode in acidic aqueous solution when it serves as the cathode of a voltaic cell is: \[2H^{+}(aq) + 2e^{-} \rightarrow H_{2}(g)\] (b) The standard hydrogen electrode (SHE) is a reference electrode with the following characteristics: 1. Hydrogen ion concentration of \(1M\). 2. Partial pressure of hydrogen gas at \(1 atm\). 3. Temperature at \(298 K\) (or \(25^{\circ}C\)). Its standard electrode potential is defined as exactly zero volts (E掳 = 0.000 V). (c) The platinum foil in a standard hydrogen electrode serves as an inert conductor that allows the flow of electrons in and out of the electrode. It also provides a surface for hydrogen gas to adsorb onto, helping maintain the required equilibrium between dissolved hydrogen ions and gaseous hydrogen molecules.

Step by step solution

01

(a) Half-reaction of a hydrogen electrode in acidic aqueous solution as cathode

To find the half-reaction occurring at the hydrogen electrode, we must remember that as the cathode, it will be the site of reduction. The reduction half-reaction for hydrogen in acidic aqueous solution can be written as: \[2H^{+}(aq) + 2e^{-} \rightarrow H_{2}(g)\]
02

(b) Standard hydrogen electrode characteristics

The standard hydrogen electrode (SHE) is a reference electrode used in electrochemical experiments, such as measuring the standard electrode potentials of other electrodes. Its characteristics are: 1. In a standard hydrogen electrode, the concentration of hydrogen ions (protons) in the solution is \(1M\). 2. The partial pressure of hydrogen gas is \(1 atm\). 3. The temperature at which the electrode operates is \(298 K\), or \(25^{\circ}C\). This electrode is used as a reference because its standard electrode potential is defined as exactly zero volts (E掳 = 0.000 V). In other words, all other electrode potentials are compared to the potential of the standard hydrogen electrode.
03

(c) Role of platinum foil in a standard hydrogen electrode

The platinum foil in a standard hydrogen electrode serves as an inert conductor that allows the flow of electrons in and out of the electrode. Platinum foil is chosen for the electrode because it is unreactive, has high conductivity, and does not oxidize. This way, platinum can facilitate the electrochemical reaction without getting consumed or altering the reaction. Additionally, it provides a surface for hydrogen gas to adsorb onto, helping maintain the required equilibrium between dissolved hydrogen ions and gaseous hydrogen molecules.

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

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

Metallic magnesium can be made by the electrolysis of molten \(\mathrm{MgCl}_{2}\). (a) What mass of \(\mathrm{Mg}\) is formed by passing a current of \(4.55\) A through molten \(\mathrm{MgCl}_{2}\), for \(3.50\) days? (b) How many minutes are needed to plate out \(10.00 \mathrm{~g} \mathrm{Mg}\) from molten \(\mathrm{MgCl}_{2}\), using \(3.50 \mathrm{~A}\) of current?

(a) Suppose that an alkaline battery was manufactured using cadmium metal rather than zinc. What effect would this have on the cell emf? (b) What environmental advantage is provided by the use of nickel-metalhydride batteries over the nickel-cadmium batteries?

Indicate whether each of the following statements is true or false: (a) If something is reduced, it is formally losing electrons. (b) A reducing agent gets oxidized as it reacts. (c) Oxidizing agents can convert \(\mathrm{CO}\) into \(\mathrm{CO}_{2}\).

Consider the reaction in Figure 20.3. Describe what would happen if (a) the solution contained cadmium(II) sulfate and the metal was zinc, (b) the solution contained silver nitrate and the metal was copper. [Section 20.3]
See all solutions

Recommended explanations on Chemistry Textbooks

Chemistry Branches

Read Explanation

Inorganic Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Nuclear Chemistry

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.