Electrochemistry

Harper and Anika are conducting a chemistry experiment. They are observing a reaction where one reactant loses electrons and the other gains them. What type of reaction are they observing?

• A reaction where both reactants get reduced.

• A reaction where both reactants get oxidized.

• A reaction that involves a transfer of electrons between reactants.

• A reaction that involves the combustion of at least one reactant.

Answer explanation

Harper and Anika are conducting a chemistry experiment. They are observing a reaction that involves a transfer of electrons between reactants. This type of reaction is known as a redox reaction. In a redox reaction, one reactant loses electrons (gets oxidized) while the other gains electrons (gets reduced). The correct choice is 'A reaction that involves a transfer of electrons between reactants.'

Abigail, Noah, and Priya are in a chemistry lab. Abigail says that reduction is a process in a chemical reaction. Can you help Noah understand what reduction is?

• It is the process where a substance gains electrons during a chemical reaction.

• It is the process where a substance loses electrons during a chemical reaction.

• It is the process where a substance creates electrons during a chemical reaction.

• It is the process where a substance destroys electrons during a chemical reaction.

Answer explanation

Reduction is the process in a chemical reaction where a substance gains electrons. In this case, the correct choice is 'It is the process where a substance gains electrons during a chemical reaction.'

In a chemistry class, Lily and Aiden were discussing a chemical reaction. Lily said that oxidation is happening in the reaction. What did she mean by oxidation?

• It is the gain of electrons.

• It is the loss of electrons.

• It is the creation of electrons.

• It is the destruction of electrons.

Answer explanation

In the given question, Lily stated that oxidation is occurring in the chemical reaction. Oxidation refers to the loss of electrons. This means that during the reaction, electrons are being lost. The other options mentioned gaining, creating, or destroying electrons, which are not correct. Therefore, Lily meant that oxidation involves the loss of electrons.

During a chemistry experiment, William and Ethan were discussing the role of a reducing agent. What is a reducing agent?

• It is the species that gets reduced -- gains electrons.

• It is the species that gets oxidized -- loses electrons.

• It is the species that creates electrons.

• It is the species that destroys electrons.

Answer explanation

A reducing agent is the species that gets oxidized, meaning it loses electrons. In this chemistry experiment, the correct choice is 'It is the species that gets oxidized -- loses electrons.' This choice highlights the role of a reducing agent in terms of electron loss.

In a chemistry experiment, Nora and Noah are trying to identify an oxidizing agent. Which of the following best describes an oxidizing agent?

• It is the species that gets reduced -- gains electrons.

• It is the species that gets oxidized -- loses electrons.

• It is the species that creates electrons.

• It is the species that loses electrons.

Answer explanation

An oxidizing agent is the species that gets reduced, meaning it gains electrons. In this chemistry experiment, Nora and Noah are trying to identify the oxidizing agent. The correct choice is 'It is the species that gets reduced -- gains electrons.' This choice accurately describes an oxidizing agent by highlighting its role in gaining electrons.

Abigail and Charlotte are learning about galvanic (voltaic) cells in their chemistry class. Michael asks them to explain what a galvanic cell is. Which of the following explanations is correct?

• It is a cell that destroys electrons on one side and creates electrons on the other side.

• It is a cell that contains only one metal bar and one aqueous ion solution.

• It is a type of battery that drives a redox reaction when electricity is applied.

• It is a type of battery that generates an electrical current from redox reactions.

Answer explanation

A galvanic cell is a type of battery that generates an electrical current from redox reactions. It is a device that converts chemical energy into electrical energy.

Ethan, Mia, and David are studying for a chemistry test. Ethan is confused about the concept of a half-reaction. Mia tries to explain it to him. Which of the following explanations given by Mia is correct?

• It is a reaction at equilibrium where half of the substances are reactants and half of the substances are products.

• It is the reaction that occurs when the switch of a galvanic cell is open.

• It shows EITHER the reduction component or the oxidation component of a redox reaction.

• It shows BOTH the reduction and oxidation components of a redox reaction.

Answer explanation

The question asks for the correct explanation of a half-reaction. A half-reaction shows EITHER the reduction component or the oxidation component of a redox reaction. This means that it focuses on one part of the reaction, either the reduction or the oxidation. The correct explanation, therefore, is that a half-reaction shows EITHER the reduction component or the oxidation component of a redox reaction. It does not show both components or represent a reaction at equilibrium.

During a science experiment, Harper and David were given two electrodes. Harper said the anode is the electrode where oxidation takes place, while David said it's the electrode where reduction takes place. Sophia, on the other hand, thought it's an aqueous solution containing an electrode or the salt bridge that connects half-cells. Who is correct?

• Harper is correct.

• David is correct.

• Sophia is correct.

• None of them are correct.

Answer explanation

The correct answer is Harper is correct. During a science experiment, the anode is the electrode where oxidation takes place. This means that Harper's statement is accurate. David's statement about reduction taking place at the anode is incorrect. Sophia's idea of an aqueous solution or salt bridge is not relevant to the definition of anode. Therefore, Harper is the only one who is correct.

During a chemistry experiment, Harper, Evelyn, and Maya are examining different electrodes. They come across a cathode. What is a cathode according to their understanding?

• It is the electrode where oxidation takes place.

• It is the electrode where reduction takes place.

• It is an aqueous solution containing an electrode.

• It is the salt bridge that connects half-cells.

Answer explanation

A cathode is the electrode where reduction takes place. In a chemistry experiment, Harper, Evelyn, and Maya were examining different electrodes and came across a cathode. The cathode is responsible for the reduction reaction. It is important to note that the cathode is not the electrode where oxidation takes place or an aqueous solution containing an electrode. Additionally, it is not the salt bridge that connects half-cells. Therefore, the correct understanding of a cathode is that it is the electrode where reduction takes place.

David, Lily, and Anika are working on a chemistry experiment. They have two solutions, one of Cu²⁺/Cu with a standard reduction potential of 0.34V and another of Zn²⁺/Zn with a standard reduction potential of -0.76V. They need to determine which of the species is going to be oxidized in their experiment. Can you help them?

• Cu

• Zn

• CuSO4

• ZnSO4

Answer explanation

In the chemistry experiment, David, Lily, and Anika have two solutions: Cu²⁺/Cu with a standard reduction potential of 0.34V and Zn²⁺/Zn with a standard reduction potential of -0.76V. To determine which species will be oxidized, they need to compare the reduction potentials. Since Zn has a more negative reduction potential than Cu, Zn will be oxidized. Therefore, the correct choice is Zn.