Question

State whether the following statements are true or false. Electrolysis brings about a chemical change.

Short answer

Answer: True.

Step-by-step solution

Define Electrolysis

Electrolysis is the process in which an electric current is passed through an electrolyte (a substance that conducts electricity), causing the ions in the electrolyte to move. This motion of ions results in the separation of ions, leading to the production of new substances at the electrodes (the positive and negative terminals).

Understand Chemical Change

A chemical change is a change that occurs in which one or more substances are transformed into new substances with different chemical properties from the original substances. Chemical changes usually involve the formation or breaking of chemical bonds.

Determine if Electrolysis Causes Chemical Change

As mentioned in Step 1, electrolysis causes the ions in the electrolyte to move and form new substances at the electrodes. This indicates new chemical bonds are being formed, and therefore, a chemical change occurs during electrolysis.

State Whether the Statement is True or False

Since electrolysis brings about a chemical change, as demonstrated by the formation of new substances at the electrodes, the statement "Electrolysis brings about a chemical change" is true.

Key concepts

Chemical Change

Chemical changes are fascinating because they create new substances. This is different from physical changes, where the substance might change its form, like ice melting into water, but it remains the same at the molecular level.
A chemical change involves the transformation of one or more substances into new substances with different properties. These changes typically occur when chemical bonds are formed or broken.

For instance, when iron rusts, it combines with oxygen from the air to create rust, which is a new substance with different properties than iron.

• They often result in color changes, temperature changes, gas production, or precipitate formation.
• Evidence of a chemical change often includes these observable signs, but not always.

During electrolysis, a classic example of a chemical change, electrical energy causes ions in an electrolyte to move, leading to the formation of different substances at the electrodes. These newly formed substances demonstrate a chemical change has occurred, confirming that electrolysis leads to chemical transformation.

Ions

Ions are charged particles that form when atoms or molecules gain or lose electrons. This process creates positive ions, or cations, and negative ions, or anions.
In a neutral atom, the number of protons equals the number of electrons. However, when an atom gains extra electrons, it becomes a negative ion because there are more electrons than protons.

Conversely, when an atom loses electrons, it turns into a positive ion due to the surplus of protons.

• Ions are crucial for various chemical processes because their charges enable them to interact and bind with other ions or molecules.
• They are also responsible for conducting electricity within an electrolyte, which is a vital part of electrolysis.

In the context of electrolysis, ions migrate towards the electrodes due to the electric current, where they undergo chemical changes to form new substances. This movement of ions is an essential component of the chemical changes happening during electrolysis.

Electrolyte

An electrolyte is a substance that contains free ions and can therefore conduct an electrical current. Electrolytes are usually found in liquid form, dissolved in water.
Common examples of electrolytes include acids, bases, and salts dissolved in a solution. These solutions can conduct electricity because the ions are free to move.

The presence of free-moving charged particles is what makes an electrolyte conductive.

• Electrolytes are crucial for various processes in chemistry, including electrolysis.
• During electrolysis, the electric current causes the ions within the electrolyte to move towards the electrodes, enabling the formation of new substances.

This property makes electrolytes essential for cells and batteries, where chemical energy is converted into electrical energy and vice versa. In everyday life, electrolytes are also crucial for biological processes, aiding in nerve function and muscle contractions.

Chemical Bonds

Chemical bonds are the attractive forces that hold atoms or ions together in a compound. The formation and breaking of these bonds result in chemical changes.
There are primarily three types of chemical bonds: ionic bonds, covalent bonds, and metallic bonds.

Ionic bonds form between ions with opposite charges, as seen in table salt, where sodium (Na⁺) bonds with chloride (Cl⁻).

• These bonds form when electrons are transferred from one atom to another, resulting in cations and anions.
• Covalent bonds, on the other hand, involve the sharing of electrons between atoms, as in a molecule of water (H₂O).

During electrolysis, the movement of ions at the electrodes can result in the breaking of existing bonds and formation of new ones. This process underlines the chemical changes that occur, demonstrating the powerful role of chemical bonds in creating new substances through electrolysis.