Consider the following galvanic cell: What happens to \(\mathscr{E}\) as the concentration of \(\mathrm{Zn}^{2+}\) is increased? As the concentration of \(\mathrm{Ag}^{+}\) is increased? What happens to \(\mathscr{E}^{\circ}\) in these cases?

Short Answer

Expert verified
When the concentration of Zn\( ^{2+} \) ions increases, the cell potential (\( \mathscr{E} \)) decreases, while the standard cell potential (\( \mathscr{E}^{\circ} \)) remains unchanged. On the other hand, when the concentration of Ag\( ^{+} \) ions increases, the cell potential (\( \mathscr{E} \)) increases, while the standard cell potential (\( \mathscr{E}^{\circ} \)) remains unchanged. This is based on the Nernst equation, which relates cell potential to ion concentrations, temperature, and the number of electrons transferred in the redox reaction.

Step by step solution

01

Write the complete cell reaction

To write the complete cell reaction, add the oxidation and reduction half-reactions, making sure the number of electrons in each half-reaction is equal: Zn(s) + 2 Ag+(aq) -> Zn^2+(aq) + 2 Ag(s) Step 2: Write the Nernst equation
02

Write the Nernst equation

The Nernst equation helps us to quantify the relationship between the cell potential (E), standard cell potential (\( \mathscr{E}^{\circ} \)), concentration of reactants and products, temperature, and the number of electrons transferred in a redox reaction. The Nernst equation is written as: \( \mathscr{E} = \mathscr{E}^{\circ} - \dfrac{0.0592}{n} \log Q \) Where: - \( \mathscr{E} \) is the cell potential at non-standard conditions - \( \mathscr{E}^{\circ} \) is the standard cell potential - n is the number of electrons transferred in the redox reaction - Q is the reaction quotient, which represents the ratio of concentrations of products to reactants Step 3: Calculate the effect of increasing Zn^2+ concentration
03

Calculate the effect of increasing Zn^2+ concentration

We will first determine the effect of increasing the concentration of Zn^2+ ions on the cell potential (E). From the Nernst equation: \( \mathscr{E} = \mathscr{E}^{\circ} - \dfrac{0.0592}{2} \log \dfrac{[Zn^{2+}]}{[Ag^+]^2} \) As the concentration of Zn^2+ increases, the value of Q increases. This then results in a decrease in the value of E because of the negative sign in front of the second term. The standard cell potential (\( \mathscr{E}^{\circ} \)) remains unchanged as it is a constant value that does not depend on the concentration of ions. Step 4: Calculate the effect of increasing Ag+ concentration
04

Calculate the effect of increasing Ag+ concentration

Now we will determine the effect of increasing the concentration of Ag+ ions on the cell potential (E): \( \mathscr{E} = \mathscr{E}^{\circ} - \dfrac{0.0592}{2} \log \dfrac{[Zn^{2+}]}{[Ag^+]^2} \) As the concentration of Ag+ ions increases, the value of Q decreases. This then results in an increase in the value of E since we have a negative sign in front of the second term. The standard cell potential (\( \mathscr{E}^{\circ} \)) again remains unchanged, as it is a constant value that does not depend on the concentration of ions. Conclusions: - As the concentration of Zn^2+ ions increases, E decreases, and \( \mathscr{E}^{\circ} \) remains unchanged. - As the concentration of Ag+ ions increases, E increases, and \( \mathscr{E}^{\circ} \) remains unchanged.

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 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

Calculate \(\mathscr{E}^{\circ}\) for the following half-reaction: $$\mathrm{AgI}(s)+\mathrm{e}^{-} \longrightarrow \mathrm{Ag}(s)+\mathrm{I}^{-}(a q)$$ (Hint: Reference the \(K_{\mathrm{sp}}\) value for AgI and the standard reduction potential for \(\mathrm{Ag}^{+}\).)

In the electrolysis of a sodium chloride solution, what volume of \(\mathrm{H}_{2}(g)\) is produced in the same time it takes to produce 257 \(\mathrm{L} \mathrm{Cl}_{2}(g),\) with both volumes measured at $50 .^{\circ} \mathrm{C}\( and 2.50 \)\mathrm{atm}$ ?

A galvanic cell consists of a standard hydrogen electrode and a copper electrode immersed in a Cu(NO \(_{3} )_{2}(a q)\) solution. If you wish to construct a calibration curve to show how the cell potential varies with \(\left[\mathrm{Cu}^{2+}\right],\) what should you plot to obtain a straight line? What will be the slope of this line?

An electrochemical cell consists of a standard hydrogen electrode and a copper metal electrode. a. What is the potential of the cell at \(25^{\circ} \mathrm{C}\) if the copper electrode is placed in a solution in which \(\left[\mathrm{Cu}^{2+}\right]=\) \(2.5 \times 10^{-4} \mathrm{M} ?\) b. The copper electrode is placed in a solution of unknown \(\left[\mathrm{Cu}^{2+}\right] .\) The measured potential at $25^{\circ} \mathrm{C}\( is 0.195 \)\mathrm{V}\( . What is \)\left[\mathrm{Cu}^{2+}\right] ?$ (Assume \(\mathrm{Cu}^{2+}\) is reduced.)

An electrochemical cell consists of a nickel metal electrode immersed in a solution with \(\left[\mathrm{Ni}^{2+}\right]=1.0 M\) separated by a porous disk from an aluminum metal electrode. a. What is the potential of this cell at \(25^{\circ} \mathrm{C}\) if the aluminum electrode is placed in a solution in which \(\left[\mathrm{Al}^{3+}\right]=7.2 \times 10^{-3} M?\) b. When the aluminum electrode is placed in a certain solution in which \(\left[\mathrm{Al}^{3+}\right]\) is unknown, the measured cell potential at \(25^{\circ} \mathrm{C}\) is 1.62 \(\mathrm{V}\) . Calculate \(\left[\mathrm{Al}^{3+}\right]\) in the unknown solution. (Assume Al is oxidized.)

See all solutions

Recommended explanations on Chemistry Textbooks

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