In this blog, we will learn about the electrochemical reaction in depth to clear this concept good enough to understand it in a way that you could be able to explain it to a 6th grade kid

Before we begin, let’s understand the following definitions first

🧪 Reactants

Reactants are the starting substances in a chemical reaction. They are the materials that undergo change during the reaction.
Example: In the reaction 2H₂ + O₂ → 2H₂O, the reactants are hydrogen (H₂) and oxygen (O₂).

🧪 Products

Products are the new substances formed as a result of a chemical reaction. They have different chemical properties compared to the reactants.
Example: In the reaction 2H₂ + O₂ → 2H₂O, the product is water (H₂O).

What is a Chemical Reaction?

🔬 Chemical Reaction

A chemical reaction is a process in which reactants are transformed into products through the rearrangement of atoms, resulting in the formation of new substances with different properties.
Example: 2H₂ + O₂ → 2H₂O

Now let’s understand this concept via a story way that even a 6th grade kid will be able to understand it,

🌟 Story: When Hydrogen and Oxygen Became Friends

Once there were two little gas friends in the air — their names were Hydrogen and Oxygen.
Hydrogen always came in a pair (like twins), and so did Oxygen.
One day, they met at a fire spark party. The spark told them,
“If you all hold hands, something cool will happen!”
So, 2 Hydrogens and 1 Oxygen held hands.
✨BOOM!✨
They magically turned into Water — something totally new!
It wasn’t just Hydrogen or Oxygen anymore. It was Water — the stuff we drink, play with, and use every day.

💧 What happened?

The old friends (Hydrogen and Oxygen) changed into something new (Water).
That change is called a chemical reaction.

🧪 Super Simple Example:

Hydrogen + Oxygen → Water

Now we know what is a chemical reaction, lets understand the types of it

Types of chemical reactions:

1. Combination Reaction
Two or more substances combine to form a single product.
Example: 2H₂ + O₂ → 2H₂O

2. Decomposition Reaction
One substance breaks down into two or more simpler substances.
Example: 2H₂O → 2H₂ + O₂

3. Displacement Reaction
A more reactive element replaces a less reactive one from its compound.
Example: Zn + CuSO₄ → ZnSO₄ + Cu

4. Double Displacement Reaction
Two compounds react and exchange their ions to form new compounds.
Example: NaCl + AgNO₃ → NaNO₃ + AgCl

5. Combustion Reaction
A substance reacts with oxygen to release heat and light.
Example: CH₄ + 2O₂ → CO₂ + 2H₂O

Now lets understand what exactly is electrochemical reaction

⚡ What is an Electrochemical Reaction?

An electrochemical reaction is a chemical reaction where electricity is produced or used during the process.

🔋 1. In Batteries (Galvanic/Voltaic Cells):

The chemical reaction produces electricity.
Example: In a battery(Galvanic cell), chemicals react inside and generate electric current to power a device.
Zinc + Copper sulfate → Electricity + Zinc sulfate + Copper
Zn + Cu²⁺ → Zn²⁺ + Cu

⚙️ 2. In Electrolysis (Electrolytic Cells):

We use electricity to make a chemical change happen.
Example: Passing electricity through water splits it into hydrogen and oxygen gases.
2H₂O → 2H₂ + O₂ (with electricity)

📚 Definition:

An electrochemical reaction is a chemical reaction that either produces electricity or uses electricity to bring about a chemical change.

Why do electrochemical reactions generate electricity?

Some electrochemical reactions generate electricity because of the movement of electrons during the reaction.

When a chemical reaction happens between two substances (like Zinc and Copper), electrons are transferred from one substance to another. These electrons don’t just disappear — they flow through a wire, and that flow is what we call electricity

🔋 Example from a Battery (Galvanic Cell):

• Zinc loses electrons (gets oxidized).
• Copper ions gain electrons (get reduced).
• The electrons that Zinc loses travel through a wire to Copper.
• That moving flow of electrons = electric current!

So, it’s the transfer of electrons between the chemicals that creates the electric flow.

⚛️ Step-by-Step Atomic-Level Process: Zinc & Copper Electrochemical Reaction

✅ Step 1: Oxidation at Zinc Electrode (Anode)

• Zinc atoms (Zn) on the surface of the zinc rod lose electrons.
• Each zinc atom becomes a Zinc ion (Zn²⁺) and dissolves into the solution.
• The electrons (e⁻) they lose are left behind in the metal rod.

Reaction:
Zn → Zn²⁺ + 2e⁻
(Oxidation – loss of electrons)

✅ Step 2: Electron Movement Through Wire

• The free electrons in the zinc rod flow through the external wire toward the copper rod.
• This flow of electrons is what we use as electricity to power devices.

✅ Step 3: Reduction at Copper Electrode (Cathode)

• The solution around the copper rod contains Cu²⁺ ions (positively charged copper ions).
• These ions are attracted to the electrons arriving through the wire.
• Each Cu²⁺ ion gains 2 electrons and becomes a neutral Copper atom (Cu).
• These copper atoms deposit on the surface of the copper rod.

Reaction:
Cu²⁺ + 2e⁻ → Cu
(Reduction – gain of electrons)

✅ Step 4: Ion Balance in Solution (Salt Bridge Role)

• The salt bridge allows ions to move between the two half-cells to keep everything neutral.
• Negative ions (e.g., SO₄²⁻) move toward the zinc side.
• Positive ions (e.g., Na⁺ or K⁺) move toward the copper side.

✅ Overall Reaction:

Zn + Cu²⁺ → Zn²⁺ + Cu

• Zinc gives electrons → becomes Zn²⁺
• Copper ions take electrons → become Cu
• Electron flow = electricity