Electrolytic Cell - Online Tutor, Practice Problems & Exam Prep

An electrolytic cell is a type of electrochemical cell that operates through electrolysis, using external electrical energy to drive non-spontaneous chemical reactions. Unlike galvanic cells, which generate electricity, electrolytic cells consume electricity and require a battery to initiate redox reactions. The cathode, where reduction occurs, is negatively charged, while the anode, where oxidation happens, is positively charged. This is due to the non-spontaneous nature of the reactions, necessitating a battery to force electron flow against the natural repulsion of like charges. Electrolytic cells are commonly found in lithium batteries and rechargeable batteries. The standard cell potential for non-spontaneous reactions in an electrolytic cell is negative, indicating that the Gibbs free energy change is greater than zero, the standard entropy change is less than zero, the equilibrium constant (K) is less than one, and the reaction quotient (Q) is less than K, all of which are indicative of non-spontaneity.

The Electrolytic Cell

So an electrolytic cell is our second type of electrochemical cell here. Now an electrolytic cell represents a non spontaneous cell that utilizes electrolysis in order to operate. Common examples, Everyday common examples of electrolytic cells would be lithium batteries or rechargeable batteries.

Now electrolysis in itself. This is where chemical reactions that consume external electrical energy in order to occur. Remember, a spontaneous reaction does not happen naturally. It needs some outside energy source to occur.

Now this is important. No matter the cell, whether it be spontaneous, which is our galvanic voltaic cell or non spontaneous, which is our electrolytic cell, the cathode is always the site of reduction and the anode is always the site of oxidation. That cannot change. Doesn't matter what type of electrochemical cell you're dealing with, this is always true. We're going to say cathode equals reduction, and we're going to say anode equals oxidation.

Electrolytic Cell Example

In a galvanic cell, the acceptance of an electron occurs at the. So if we're accepting an electron, that means that's reduction. Reduction occurs at the cathode and in an electrolytic cell it occurs at the blank.

So remember, it doesn't matter the type of electrochemical cell, whether it be galvanic, voltaic, or electrolytic, reduction always occurs at the cathode and oxidation always occurs at the atom. In this case, the answer is a its reduction, so it's going to recur. It's going to occur at Decathlon for either one of these types of electrochemical cells.

Electrolytic Cell Components

Now, electrolytic cells use the same major components as galvanic cells, but still possess some key differences. Key difference #1 is that an electrolytic cell consumes electricity and requires a battery to drive the reaction forward. So a galvanic cell produces electricity and so it has a voltmeter which reads the amount of electricity generated, an electrolytic one. It consumes electricity, so it requires an actual battery to drive the reaction forward.

Key difference #2. It uses stored electrical energy, the energy found like in this battery, and converts it into chemical energy so that it can create a redox reaction that really doesn't want to occur. Doesn't want to occur because that's our key difference #3. The process is non spontaneous and because of this the cathode is negatively charged and the anode is positively charged. So if we take a look here again, our cathode is negative, our anode is positive, but the anode is still losing electrons giving them to the cathode.

But negative electrons don't want to go to a electrode that's negative. Light charges repel. That's why we need a battery to supply the energy to force this non spontaneous process to occur. So here we still have our copper oxidized as oxidation is still occurring at the anode to copper 2 plus. So copper solid to copper 2 plus aqueous. With the two electrons in the Catholic department we still have reduction so 10/2 is reduced to 10 solid. So 10/2 plus aqueous absorbs 2 electrons to become tin solid.

We still have our salt bridge where the negative neutral ion moves towards the anode compartment to neutralize the build up of cations, in this case copper, 2 ions in solution. We still have the positive ions moving over to this way, building up a little bit here to help keep driving the electrons over to the cathode side. Here our overall reaction after we cancel out our intermediate electrons comes out to be copper solid. Plus 10/2 aqueous gives me copper 2 plus aqueous plus 10 solid. So there are some things that are the same, but these are the key differences you need to keep in mind when dealing with an electrolytic cell.

Cu 2 + ( aq ) + Sn 2 + ( aq ) → Cu 2 + ( aq ) + Sn ( s )

Electrolytic Cell Example

Which of the following is true about an electrolytic cell? So here it has a positive Catholic. Remember, for an electrolyte cell, the cathode is no longer positive, it's negatively charged.

It has no salt bridge and still hasn't salt bridge. Capital plates out. Remember, at the cathode we still have reduction occurring. So yes, we still have the plating out of our cathode has a negative anode. Nope. The anode now is positively charged.

So there are some key differences between an electrolytic cell and a galvanic cell. But one thing that remains the same is that the anode is the site of oxidation. So the anode dissolves away and the cathode is a site of reduction.

The cathode plates out, so keep that in mind when you're looking at an electrolytic cell or galvanic cell that remains the same for both.

Electrolytic Cells and Spontaneity

Here we're going to say that an electrolytic cell uses non spontaneous reactions and as a result of this it's consuming electricity. Now all non spontaneous reactions have a negative standard cell potential value. So if we're talking about an electrolytic cell, remember it's non spontaneous.

Here we can relate this idea to other variables. Gibbs free energy, entropy, our equilibrium constant, and our reaction quotient Q besides our standard cell potential. So here to be non spontaneous, the change in our standard Gibbs free energy would have to be greater than 0. For changing our standard entropy of the universe, or total, it would be less than 0.

K would have to be less than one. It would also be less than Q and again we said negative standard cell potential. So here to be negative it had been less than 0. So these are the relationships that we can talk about when it comes to an electrolytic cell, and spontaneity when it comes to these different types of variables.

Electrolytic Cell Example

Here it says if the standard cell potential which is E_cell for the given redox reaction is -0.54 V, which of the following statements is true right? So here our standard self potential is less than 0, which means that we are non spontaneous.

The redox reaction will have an equilibrium constant value that is greater than one. No. If we're non spontaneous, it should be less than one. The redox reaction will produce electricity. If you are non spontaneous, you will consume electricity, not produce it.

C is correct because here since we're non spontaneous, your equilibrium constant K should be less than one and then here the redox well the reaction quotient will be less than the equilibrium constant. Remember K is greater than Q. Then you're spontaneous, not non spontaneous. So this would be spontaneous, which is not the case in this question. So C would be our answer.

OK, all the other things would only be true if we were spontaneous. But since our standard equilibrium, since our standard cell potential is less than 0, we are non spontaneous.

​If the overall redox reaction for an electrolytic cell is given below, what will happen to the mass of the cobalt electrode?

Co²⁺ (aq) + Cu (s) ⇌ Co (s) + Cu²⁺(aq)

• A. Its mass will increase. 
• B. Its mass will decrease. 
• C. Its mass will remain constant. 
• D. Not enough information is given.​

Here’s what students ask on this topic:

Where does reduction occur in an electrolytic cell?

In an electrolytic cell, reduction occurs at the cathode. This is the electrode where positively charged ions, or cations, gain electrons and are reduced. The process of reduction involves the gain of electrons, which decreases the oxidation state of the substance. Since cations are attracted to the cathode, they migrate towards it, where they receive electrons from the power source that's driving the electrolytic process. This electron gain results in the reduction of the cations into a neutral state or a lower oxidation state. Remember, you can use the mnemonic "Red Cat" to help recall that Reduction occurs at the CAThode in an electrolytic cell.

What are some of the necessary components of an electrolytic cell?

An electrolytic cell is a device that drives a non-spontaneous chemical reaction through the application of electrical energy. The necessary components of an electrolytic cell include:

1. Electrodes: There are two electrodes, the anode and the cathode. The anode is the electrode where oxidation occurs, and electrons are given up to the power source. The cathode is where reduction takes place, and electrons from the power source are accepted.
2. Electrolyte: This is the medium that contains ions, which can be a liquid or a molten salt that conducts electricity. The electrolyte provides the ions that are necessary for the chemical reaction.
3. Power Source: A direct current (DC) power supply, such as a battery or rectifier, is needed to provide the energy to drive the non-spontaneous reaction.
4. Container: A vessel that holds the electrodes and the electrolyte, ensuring that the reaction can occur in a controlled environment.
5. Conducting Wires: These connect the electrodes to the power source, allowing the flow of electrons into and out of the electrolytic cell.
6. Salt Bridge (optional): In some cells, a salt bridge is used to maintain the electrical neutrality of the electrolyte solutions during the reaction process.

Understanding the function of each component is crucial for manipulating

What kind of reaction occurs in an electrolytic cell?

In an electrolytic cell, an electrochemical reaction that requires the input of electrical energy to proceed is carried out. This type of reaction is known as an electrolysis reaction. During electrolysis, an external voltage is applied to drive a non-spontaneous chemical reaction. This contrasts with galvanic or voltaic cells, where the reaction is spontaneous and generates electrical energy.

In an electrolytic cell, the anode is the positive electrode, and the cathode is the negative electrode. When the current is applied, positive ions (cations) move towards the cathode and gain electrons in a reduction reaction, while negative ions (anions) move towards the anode and lose electrons in an oxidation reaction. Common applications of electrolytic cells include the decomposition of water into oxygen and hydrogen gas, electroplating, and the production of chemicals like chlorine and sodium hydroxide.

Does the diagram above represent an electrolytic cell in which the reaction?

The question seems to be referring to a diagram that isn't visible in this context. However, I can explain what an electrolytic cell is and how you can identify one.

In an electrolytic cell, electrical energy is used to drive a non-spontaneous chemical reaction. This is the opposite of a galvanic or voltaic cell, where a spontaneous reaction generates electrical energy. To identify an electrolytic cell in a diagram, look for a few key components:

1. Power Source: An external battery or power supply is connected to two electrodes, indicating the need for an external electric current to induce the reaction.
2. Electrodes: There should be two electrodes, an anode and a cathode, typically labeled and placed in a solution (electrolyte). In an electrolytic cell, the anode is positive, and the cathode is negative, which is the reverse of a galvanic cell.
3. Electrolyte: This is the medium (usually a liquid) that contains ions which can move to carry electric charge between the electrodes.
4. Chemical Reaction: The diagram may also show a non-spontaneous reaction occurring at the electrodes, such as the decomposition of water into hydrogen and oxygen gases.

If the diagram includes these features, it likely represents an electrolytic cell. Remember, the key distinction