A storm has knocked out power to your beach house, and you would like to build a battery from household items to charge your iPhone. You have the following materials. alum in the kitchen, which can be used to make a 1.0 M Al 3+ solution bleach, which is a solution that is approximately a 1.0 M in ClO - aluminum foil, a platinum necklace and bologna, which can be used as a salt bridge (a) What are the half-reactions and overall reaction in the battery?

Hello everyone on this problem being asked what our half reactions for our boundary and the overall reaction is. So the safety matches contain k C L 03. So the solution of all, of course contain K plus and cl oh three ions. Let's go ahead and actually write this reaction out. So regarding the KCL- 03, we have the k c L 03 of course as our starting reagent. And this yields the K plus K ions as well as the c l 03 minus and ions. So since this here is an oxidizing agent, it will be the cattle compartment so I can accept electrons from the anodes. So this gives us our next reaction. I'll just play maybe one and 2 here. So then we have the cielo three minus which is reacting with six moles of H plus As well as five electrons. And this yield have a mole of our cl two and three moles of H 20 in its liquid state. The standard reduction potential value here is equal to 1. volts. So electrode that he must put or uses platinum jewelry, we cannot use aluminum as a cathode here because aluminum will react with the liberated cl two gas. So aluminum will produce a solution of a L three plus ions. So here we're talking about the aluminum. So here we have the aluminum three plus reacting with three electrons. And this yields are neutral metal of aluminum. The standard reduction potential value here is equal to negative 1. volts. So aluminum will be the anodes. Since it has a lower center reduction potential value. And since center reduction potentials are always written as a reduction reactions, the reactions that we have will be reversed. So this then becomes aluminum solid, which yields a L three plus which is eight and three electrons. We're gonna go and also flip this reduction value. So it'll be a positive 1.66 volts. We can see then that the catholic reaction has five electrons and the annual reaction has three electrons. So to get the overall reaction we must make the numbers of electrons equal so they can cancel. Go ahead and scroll down here from our space. So the overall reaction then is taking the CLO -. That is a quiz, acting with six moles of H. Plus And the five electrons. This yields half a mole of our cl two As well as three moles of H 20. The standard reduction value here is equal to 1.47V. That for other reaction, we have the aluminum and it's solid state which yields aluminum three plus As well as three electrons. And this given state reduction potential value is 1.66V. Again, we're trying to make the number of electrons equal to each other. So we're gonna go ahead and multiply all of this by three. And the second reaction by five. Then our night reaction here Is that we have three moles of CO03 - in its estates, as well as five moles of aluminum solid. Then we have 18 moles of H. Plus. This is all just for the starting reagents for my products here. We have five moles of our aluminum three plus, as well as three have our cl two and it's cash in states and lastly nine moles of our H 20 in its liquid state. So then cross anything out here because we are being asked to provide the half reaction values. So I'll go ahead and highlight this half reaction as well as this one here. And the problem also asked for the net reaction and that's the one at the bottom. So these three here are going to be my final answers for this problem.

Ch.19 - Electrochemistry

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McMurry 8th Edition

Ch.19 - Electrochemistry

Problem 121a

Chapter 19, Problem 121a

A storm has knocked out power to your beach house, and you would like to build a battery from household items to charge your iPhone. You have the following materials. alum in the kitchen, which can be used to make a 1.0 M Al³⁺ solution bleach, which is a solution that is approximately a 1.0 M in ClO^-aluminum foil, a platinum necklace and bologna, which can be used as a salt bridge (a) What are the half-reactions and overall reaction in the battery?

Verified step by step guidance

Identify the possible redox pairs from the materials available: Al/Al^{3+} and ClO^-/Cl_2.

Write the oxidation half-reaction: Al \rightarrow Al^{3+} + 3e^-.

Write the reduction half-reaction: ClO^- + 2H_2O + 2e^- \rightarrow Cl_2 + 4OH^-.

Balance the electrons between the oxidation and reduction half-reactions by multiplying the oxidation half-reaction by 2 and the reduction half-reaction by 3.

Combine the balanced half-reactions to write the overall redox reaction.

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Key Concepts

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

Electrochemical Cells

Electrochemical cells convert chemical energy into electrical energy through redox reactions. They consist of two electrodes: an anode where oxidation occurs and a cathode where reduction takes place. Understanding how these cells function is crucial for determining the half-reactions and overall reaction in a battery setup.

Half-Reactions

Half-reactions represent the individual oxidation and reduction processes occurring in an electrochemical cell. Each half-reaction shows the transfer of electrons and the change in oxidation states of the reactants. Identifying these half-reactions is essential for balancing the overall reaction and understanding the flow of electrons in the battery.

Salt Bridge

A salt bridge is a component of an electrochemical cell that maintains electrical neutrality by allowing the flow of ions between the two half-cells. It typically contains a gel or solution of an inert electrolyte. In this scenario, using bologna as a salt bridge helps facilitate ion movement, which is vital for the battery's operation.