Question

The violent reaction between sodium and water is an example of (1) Reduction (2) Oxidation (3) Redox reaction (4) Neutralisation reaction

Short answer

The reaction is a redox reaction.

Step-by-step solution

Identify the Reaction

The reaction between sodium and water involves the formation of sodium hydroxide and hydrogen gas. Write the chemical equation: \[ 2Na + 2H_2O \rightarrow 2NaOH + H_2 \]

Analyze Oxidation-Reduction Process

Determine if oxidation or reduction occurs. In this reaction, sodium loses electrons (oxidation) and water gains electrons to form hydrogen gas (reduction).

Classify the Reaction

Since the reaction involves both oxidation (sodium) and reduction (water), it is classified as a redox reaction.

Key concepts

Oxidation

Oxidation is a process where an atom or molecule loses electrons. In simple terms, when something undergoes oxidation, it gives away electrons. This process is crucial in various chemical reactions, including our example with sodium and water. When sodium reacts with water, sodium atoms lose electrons and form sodium ions. You can think of oxidation as the process that makes something lose an electrical charge. The substance that loses electrons is oxidized. In our chemical equation: 2Na → 2Na⁺ + 2e⁻ We see that sodium (Na) changes into sodium ions (Na⁺) by losing electrons (e⁻). It's essential to remember that oxidation doesn't always mean combining with oxygen. It mainly refers to losing electrons.

Reduction

Reduction is the opposite of oxidation. It happens when an atom or molecule gains electrons. When something is reduced, it essentially means that it is gaining electrical charge. In the sodium and water reaction, water molecules gain electrons and split into oxygen and hydrogen. Specifically, the hydrogen ions in water (H₂O) gain electrons to form hydrogen gas (H₂). The chemical breakdown looks like: 2H₂O + 2e⁻ → H₂ + 2OH⁻ This shows that water (H₂O) receives electrons (e⁻) and is reduced during the reaction. The substance that gains electrons is reduced. It's interesting to note that both oxidation and reduction occur simultaneously in a redox reaction.

Chemical Equation

A chemical equation summarizes a chemical reaction using symbols and formulas. It shows the reactants (starting materials) and products (ending materials) of a reaction. For the sodium and water reaction, the chemical equation is: 2Na + 2H₂O → 2NaOH + H₂ Here's how to read this equation:

• 2Na represents two sodium atoms.
• 2H₂O represents two water molecules.
• 2NaOH represents two units of sodium hydroxide.
• H₂ represents hydrogen gas.

The equation tells us that two molecules of sodium react with two molecules of water to produce two molecules of sodium hydroxide and one molecule of hydrogen gas. It's balanced, meaning the number of each type of atom is the same on both sides of the equation. Balancing chemical equations is crucial for accurately representing the conservation of mass.

Sodium and Water Reaction

The reaction between sodium and water is a classic example of a redox reaction. It is quite violent and produces heat, hydrogen gas, and sodium hydroxide. When sodium comes in contact with water, it floats and starts to fizz. This fizzing is due to the production of hydrogen gas. The overall reaction is: 2Na + 2H₂O → 2NaOH + H₂ Here's a closer look at what happens:

• Sodium (Na) reacts with water (H₂O).
• Sodium loses electrons (oxidation) and water gains electrons (reduction).
• Heat is released, causing hydrogen gas (H₂) to form and evaporate quickly.
• Sodium hydroxide (NaOH) is produced and remains in solution.

This reaction is highly exothermic, meaning it releases a lot of energy. That's why it can be dangerous if not controlled properly. Always handle sodium with care and under supervision in a laboratory setting.